Language：English   Publishing type：Research paper (scientific journal)  

Benthic diatoms are beneficial organisms whose activity supports ecosystems and improves water quality. The
pennate diatom Nitzschia palea is an important diatom species, as it has a potential to control cyanobacterial
blooms. Several studies have attempted to restore lakes by using artificially produced substrates that remove
nutrients or harmful substances. Although substrates provide attachment sites, they may adversely affect the
growth of diatoms by removing nutrients. In this study, we investigated a suitable substrate for N. palea growth.
Substrates such as glass beads, activated carbon, and oyster shells, which can be used for lake water or ecosystem
restoration, were selected. The most suitable substrate was determined from the perspective of nutrient
adsorption, elution, and availability of adhesion sites. N. palea was cultivated with substrates until the stationary
growth phase was attained, and N. palea growth and the change in nutrient content of the medium were
investigated. Silicate eluted from small glass beads considerably increased the maximum cell yield of N. palea
(7.03 × 106 cells mL􀀀 1). Activated carbon absorbed nitrate from the medium and decreased the specific growth
rate of N. palea from 0.47 d􀀀 1 (without substrate) to 0.24 d􀀀 1 while providing attachment sites and increasing the
maximum cell yield compared to the control (1.49 × 106 and 1.01 × 106 cells mL􀀀 1 under activated carbon and
control treatments, respectively). Oyster shells absorbed phosphate and did not increase the maximum cell yield.
Our results suggest that submerged substrates that absorb nutrients may negatively affect the growth of attached
diatoms. Therefore, when using the substrates for lake water restoration, attention must be paid to the growth of
attached diatoms.

DOI： https://doi.org/10.1016/j.ecoleng.2022.106743

Other Link： https://www.sciencedirect.com/science/article/pii/S092585742200204X

Language：English   Publishing type：Research paper (scientific journal)  

Remediation of water quality by stimulating algal photosynthesis using light-emitting
diodes (LEDs) has attracted attention, but few studies have examined this in outdoor freshwater
environments. To understand the effects of LED illumination on water quality, the dissolved oxygen
(DO), temperature, pH, and electric conductivity were monitored over 5 months in three depressions
with or without a red/blue LED light at the bottom of an experimental pond. The effects of the blue
LED on water quality were evident in the period with less rainfall after the change of water quality to
an equilibrium state; DO and pH were higher, and EC was lower for the blue LED than for the control.
The diel changes of these variables were also lower for the blue LED. The effects of the red LED on
DO and pH were also evident, but to a lesser extent compared to those of the blue LED. A vertical
mixing of water associated with a nighttime cooling of the surface water was suggested by a rapid
DO increase after a temperature decrease in the control. Such internal water circulation and an inflow
of water after rainfall might have obscured the LED effects in the rainy period. The bottom water of
the blue LED had a higher density and species richness of phytoplankton than that of the control
at the end of the experiment. A lower density of phytoplankton and higher nutrient concentrations
in the red LED might have been due to a higher density and feeding activity by zooplankton. Our
results confirmed the applicability of LED illumination in stimulating algal photosynthesis, and in
improving the oxygen condition of the bottom water in freshwater ponds.

DOI： https://doi.org/10.3390/w14152310

Language：English   Publishing type：Research paper (scientific journal)  

Lake eutrophication is associated with cyanobacterial blooms. The pennate
diatom Nitzschia palea (N. palea) inhibits the growth of the cyanobacterium
Microcystis aeruginosa (M. aeruginosa); therefore, increasing the relative abundance
of N. palea may contribute to the inhibition of Microcystis blooms. Several
studies have demonstrated that blue light irradiation promotes diatom
growth and inhibits cyanobacterial growth. In this study, we evaluated the
effects of blue light irradiation on N. palea and M. aeruginosa abundance.
Monocultures and co-cultures of N. palea and M. aeruginosa were exposed to
blue light and fluorescent light at 32 μmol photons m2 s1. The relative abundance
of N. palea under fluorescent light decreased gradually, whereas the
abundance under blue light was relatively higher (approximately 74% and 98%
under fluorescent light and blue light, respectively, at the end of the experiment).
The inhibition efficiency of blue light on the growth rate of
M. aeruginosa was related to the light intensity. The optimal light intensity
was considered 20 μmol photons m2 s1 based on the inhibition efficiency of
100%. Blue light irradiation can be used to increase the abundance of N. palea
to control Microcystis blooms.

DOI： https://doi.org/10.1002/wer.10707

Repository Public URL： http://hdl.handle.net/2324/4796027

Language：Japanese   Publishing type：Research paper (scientific journal)  

Cs Adsorption Capability of Activated Charcoal and its Incineration Volume Reduction Ratio and Cs Recovery Ratio

Language：Japanese   Publishing type：Research paper (scientific journal)  

Effect of Atmospheric Pressure Non Equilibrium Plasma Treatment for Activated Carbon and Bamboo Charcoal on Cesium Adsorption

Language：English   Publishing type：Research paper (scientific journal)  

In this study, cost-effective cellulosic biomass based activated wood charcoal was developed from Japanese Sugi tree (Cryptomeria japonica) by concentrated nitric acid modification for adsorption of Cs from contaminated water. The physicochemical properties of specimens were investigated using N2 adsorption-desorption isotherms (BET method), FESEM, FTIR, and XPS spectra analysis. The experimental results revealed that the surface area of the raw wood charcoal was significantly decreased after boiling nitric acid modification. However, several oxygen-containing acidic function groups (-COOH, -CO) were introduced on the surface. The adsorption study confirmed that the equilibrium contact time was 1 h, the optimum adsorption pH was neutral to alkaline and the suitable adsorbent dose was 1:100 (solid: liquid). The maximum Cs was removed when the concentration of Na and K were lower (5.0 mM) with Cs in solution. The Cs adsorption processes well approved by the Langmuir isotherm and pseudo-second-order kinetic models and the maximum adsorption capacity was 35.46 mgg-1. The Cs adsorption mechanism was clearly described and it was assumed that the adsorption was strongly followed by chemisorptions mechanism based on the adsorbent surface properties, kinetic model and Langmuir isotherm model. Most importantly, about 98% of volume reduction was obtained by burning (500 °C) the Cs adsorbed charcoal, which ensured safe storage and disposal of radioactive waste. Therefore, this study can offer a guideline to produce a functional adsorbent for effective Cs removal and safe radioactive waste disposal.

DOI： 10.1016/j.chemosphere.2020.127801

Language：English   Publishing type：Research paper (scientific journal)  

To evaluate the effect of microorganism adherent carrier for Nitzschia palea on the control of Cyanobacterial
blooms, the changes of phytoplankton population structure and the chlorophyll a concentration after carrier
installation were compared with those without carrier installation in field and laboratory experiments. The results
showed that the installation of the carrier could control the growth of Microcystis spp., effectively. In the
field investigation, the cell number of Microcystis spp. can decrease to 54,800 cells/mL after 5 d treatment
comparing to 464,000 cells/mL in water without treatment, but the installation of adherent carrier did not influence
the growth of other phytoplanktons including Chlorophyta. Through the observation by a microscope,
the adhesion of the Nitzschia palea to this carrier was observed as well as the gliding movement of the Nitzschia
palea onto the colonies of Microcystis, indicating that the adhesion, invasion and sliding movement of Nitzschia
palea induced the physical destruction and effective control of Microcystis colony. Overall, the installation of this
carrier can promote the growth of Nitzschia palea near carrier fiber, and control cyanobacterial blooms by the
invasion of Nitzschia palea onto Microcystis colony, which can be used as one of energy-saving and sustainable
eco-engineered blue-grass control methods in closed water areas such as lakes and reservoirs.

DOI： https://doi.org/10.1016/j.ecoleng.2020.106127

Other Link： https://doi.org/10.1016/j.ecoleng.2020.106127

Language：Japanese   Publishing type：Research paper (scientific journal)  

Physiological characteristics of diatom Nitzschia palea for ecological engineering countermeasure method of water blooms

Language：English   Publishing type：Research paper (scientific journal)  

This study reported a novel synthetic zeolite based adsorbent developed from the municipal wastewater sludge molten slag (bio-slag) through the hydrothermal modification process for removal of cesium (Cs) from simulated wastewater. The artificial zeolites were produced from the raw bio-slag which was identified by the several physicochemical experimental procedures such as the surface area analysis (the BET technique), the FESEM, the XRF and the XRD. The Cs adsorption process of modified bio-slag was exmined by the linear pseudo-first order, pseudo-second order and intra-particles diffusion models whilst the second order kinetic model confirmed a better agreement with the correlation coefficient, R² = 0.999-1.000 for 20-400 mg/L Cs solution. The Langmuir, Freundlich and the Temkin isotherm model were investigated using the adsorption isotherm data. A satisfactory correlation coefficient value (R²= >0.980) proved that the isotherm parameters were perfectly fitted to the Langmuir and Freundlich model and the highest Cs adsorption ability of modified bio-slag were 51.02, 51.02 and 49.51 mg/g at 288, 298 and 308 K, respectively. The better agreement of adsorption data with the second order kinetic model and the Langmuir model proved the adsorption mechanism was controlled by the chemical reaction (ion-exchange). Thermodynamic studies under the different temperatures proved that the adsorption reaction was endothermic (ΔH =20.53 kJ/mol) and ΔS = 0.021 kJ/mol/K) and non-spontaneous (ΔG>0). Moreover, the modified bio-slag effectively removed Cs even in the co-existence of Na⁺ and K⁺ as competitive ions at their wide range of concentrations (upto 300 mM) although the higher concentration slightly affected the Cs adsorption.

DOI： 10.1016/j.jwpe.2019.101055

Language：Japanese   Publishing type：Research paper (scientific journal)  

The competition characteristic of diatom Nitzschia palea and water blooms and the growth inhibition effect of LED Irradiation on cyanobacteria Microcystis aeruginosa

DOI： 10.2208/jscejer.75.7_III_97

Language：English   Publishing type：Research paper (international conference proceedings)  

This study reports the production ol synthetic zeolrte from sewage sludge molten slag (bio-slag) by alkali hydrothernral treatment. The bio-slag is treated with 1.0 N NaOH at 140C for 24 hr. The zeolite properties of modified bio-slag were identified by using surface area measurenrent, FESEM observation, XRF, XRD investigation and cation exchange capacity [CEC] analysis. The experimental results exhibit that the sutface area and the pore volume of the modified bio-slag increased almost 10 times. The FESEM obserwations showed that the modified bio-slag is highly porous. The XRF analysis indicates that the ratio of SiO2/Al23 in the slag is improved from 2.52 to 2.96 after the modification process which increases the strength of zeolite structure. The XRD analysis confirms that the zeolite X, zeolite Y, zeolite A, and sodalite were formed on the surface of the modified bio-slag. Importantly, the CEC of the modified bio-slag drastically improved almost 2 times due to the formation of synthetic zeolites. Therefore, the developed synthetic zeolite could be used as an emerging material for wastewater treatment, soil decontamination etc.

Other Link： https://itma.upm.edu.my/activities/isamn_2019_3rd_international_symposium_on_advanced_materials_and_nanotechnology-19103?L=en

Language：English   Publishing type：Research paper (scientific journal)  

This study investigates the effective removal of cesium (Cs) from aqueous solution using sewage sludge molten (SSM) slag that has undergone the surface modification with alkali (NaOH) hydrothermal treatment. The raw and modified slags were characterised systematically using the BET method, the FESEM, the XRF, the XRD spectroscopy and the CEC analysis to understand the physicochemical changes of the materials, and its sensitivity to Cs ions adsorption. Batch adsorption experiments were carried out to investigate the effects of adsorbent dose, contact time, solution pH, different initial Cs concentrations, temperature and the effect of competitive ions on Cs adsorption. The adsorption isotherm, kinetic and thermodynamic studies were also evaluated based on the experimental results. A higher Cs removal efficiency of almost 100% (for 20–100 mg/L of initial concentration) was achieved by the modified SSM slag, and the maximum adsorption capacity was found to be 52.36 mg/g. Several types of synthetic zeolites such as zeolite X, zeolite Y, zeolite A, and sodalite were formed on surface of the modified slag through the modification process which might be enhanced the Cs adsorption capacity. Kinetic parameters were fitted by the pseudo-second order model. The adsorption isotherms data of modified slag were well-fitted to the Langmuir (R² = 0.989) and Freundlich isotherms (R² = 0.988). The thermodynamic studies indicated that the adsorption process by the modified slag was spontaneous and exothermic. In the competitive ions effect, the modified slag effectively captured the Cs ion in the presence of Na⁺ and K⁺, especially at their lower concentrations. Moreover, the modified slag was reused for several cycles after the successful elution process with an appropriate eluting agent (0.5 M H₂SO₄), without deterioration of its original performance. Therefore, the SSM modified slag could be effectively used as a low-cost potential adsorbent for high Cs adsorption from wastewater.

DOI： 10.1016/j.jenvman.2018.05.059

Language：English   Publishing type：Research paper (scientific journal)  

In this study, the air oxidized bamboo charcoal (BC) was investigated for cesium (Cs) adsorption from aqueous solution. The physicochemical properties of the adsorbent were evaluated systematically using the different techniques including BET, FESEM, FTIR, XPS and also the pHpzc value. Batch adsorption experiments were conducted to determine the effect of contact time, solution pH, initial Cs concentrations, temperature and also the presence of competitive ions on adsorption. The adsorption kinetic parameters confirmed the better fitting of pseudo-second order kinetic model. The isotherm data could be well described by the Langmuir isotherm model and the maximum monolayer adsorption capacity was 55.25 mg g^-1. The high specific surface area and the porous structure with some acidic functional groups on the surface were obviously responsible for high Cs adsorption onto oxidized-BC. Thermodynamic parameters such as standard enthalpy, entropy, and Gibbs free energy were evaluated and it had been found that the adsorption process was favorable, spontaneous and endothermic in nature. In the competitive ions study, the presence of Na and K with their concentrations up to 12mM did not strongly affect the removal of Cs by oxidized-BC. Therefore, the experimental results suggested that the oxidized-BC could be used as an effective adsorbent for significant Cs removal from aqueous solution considering the high adsorption capacity, short adsorption time and selective removal of Cs ions.

DOI： 10.1016/j.wri.2018.01.001

Other Link： https://www.sciencedirect.com/science/article/pii/S2212371717301348

Language：English   Publishing type：Research paper (scientific journal)  

Aquaculture has become one of the major sources of lake eutrophication, due to the lack of direct and efficient technologies for pollution control and remediation. This study proposes a novel ecological dam (Eco-dam) system, which consists of biofilter floating beds and plant floating beds that form an enclosure (the test zone) around the breeding area that allows lake water to pass through. A pilot-scale test was conducted to test pollution control and in situ bioremediation during breeding of Chinese mitten crab (Eriocheir sinensis) in Yangcheng Lake, China. The results showed slight improvement of water quality in the test zone compared with the breeding zone. The biofilm that formed on the biofilter played a major role in removal of organic pollutants and nitrogen (0.609 kg COD/(m²·d), 0.512 kg NH₄⁺-N/(m²·d), 0.482 kg NO₂⁻-N/(m²·d), and 0.112 kg NO₃⁻-N/(m²·d)). Both proteins and volatile suspended solids (VSS) in the Eco-dam biofilm decreased from the water surface towards the lake bottom, especially below 0.5 m depth. The average ratio of VSS to suspended solids in the biofilm was 0.337 ± 0.025 g/g. Analysis with the Illumina MiSeq System confirmed the presence of a diverse microbe population in the biofilm, performing organic carbon removal and nitrification and denitrification, with limited photosynthesis near the lake surface and methane oxidation near the lake bottom.

DOI： 10.1016/j.jclepro.2017.11.185

Language：English   Publishing type：Research paper (scientific journal)  

The surface chemistry and the structural properties of activated carbon can be altered by the acidic modification. The objective of this study is to investigate the changes occurring in bamboo charcoal (BC) during activation with concentrated nitric acid. Low temperature (500˚C) carbonized BC has been prepared and oxidized with 70% concentrated boiling nitric acid (BC-AC). The porous properties of the BC are analyzed with nitrogen adsorption isotherm at 77 K. The surface structure is observed by Field emission scanning electronic microscope (FESEM) and the surface functional groups are examined by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and the pH of the point of zero charge (pHPZC). The results reveal that severe oxidation with HNO3 considerably decreases the surface area of BC with enhanced pore widening and FESEM observation demonstrates the erosive effect of oxidation. The FTIR analysis detects that some absorption bands are assigned for carboxyl, aldehyde and ketone groups on BC-AC. The XPS analysis also clearly shows that the ratio of oxygen and acidic functional groups has been enriched significantly on the BC-AC. The low pHPZC value of BC-AC confirms that the surface is highly acidic for the fixation of acidic functional groups on surface. In general, the existence of the abundant amount of acidic functional groups on adsorbents enhances the sorption of heavy metals ions in aqueous solution. Therefore, it is strongly expected that the modified BC, activated under the proposed conditions would be a promising ion exchanger in aqueous solution and can be applied for the adsorption of different heavy metal ions and radioactive materials from effluent.

Other Link： http://iopscience.iop.org/article/10.1088/1755-1315/82/1/012002/pdf

Language：English   Publishing type：Research paper (scientific journal)  

The study is conducted to explore the potential of bamboo charcoal (BC) as an adsorbent to remove cesium from aqueous solution. Low temperature carbonized BC (500°C) is prepared and the surface of the BC is modified with 70% concentrated boiling nitric acid (BC-AC). Specific surface area, field emission scanning electron microscope (FESEM), fourier transform infra-red (FTIR) spectroscopy, and point of zero charge (pHpzc) of BC and BC-AC have been investigated in this study. The results demonstrate that BC-AC is enriched with oxygen-containing functional groups but its porous structure and surface area are decreased when compared with the raw BC. Optimum cesium adsorption conditions onto BC and BC-AC have been determined by investigating the contact time, pH of solution, adsorbent dosage and initial solution concentration in batch adsorption process. It has been observed that maximum cesium adsorption capacity is 0.17 and 45.87 mg/g for BC and BC-AC, respectively. It has also been observed that almost 100% cesium could be removed from water at up to 400 mg/L concentrated cesium solution by BC-AC whereas the removal capacity of cesium by BC is very poor. The experimental adsorption data of both BC and BC-AC follows the pseudo-second-order kinetic. The Freundlich adsorption equilibrium isotherm data is more appropriate than the Langmuir isotherm for adsorption of cesium by BC. However, adsorption isotherm data for BC-AC is a better fit with Langmuir isotherm than the Freundlich isotherm model. Furthermore, the separations factor (RL) and the surface coverage (θ) for Langmuir isotherm confirms that the proposed adsorption process is the most suitable for BC-AC. This study suggests that BC-AC could be effectively used for the removal of cesium from environmental water.

DOI： http://dx.doi.org/10.1016/j.jece.2017.02.014

Other Link： http://ac.els-cdn.com/S2213343717300659/1-s2.0-S2213343717300659-main.pdf?_tid=f77455a8-4454-11e7-bb02-00000aab0f6b&acdnat=1496051917_b222784360d28cdd657a135f01d94eaf

Language：Japanese   Publishing type：Research paper (scientific journal)  

WATER PURIFICATION BY LED IRRADIATION IN DECOMPOSING WITHERED MICROCYSTIS

Language：Japanese   Publishing type：Research paper (scientific journal)  

一般に、ダムとは、川の水の流れを堰き止めて貯留し、水量を安定化させるためのシステムを指します。一方、私たちが提案している「生態工学ダム」は、汚濁負荷源からの栄養塩や有機物を堰き止めて、水質を安定化させるためのシステムです。汚濁負荷の削減に加え、循環資源化や地域活性化をも目指しています。

Language：Japanese   Publishing type：Research paper (scientific journal)  

The purpose of this study is to identify whether the released Poly-P can be crystallized as MAP and to evaluate its forming ability.

Language：English   Publishing type：Research paper (scientific journal)  

POSSIBLE SURVIVAL MECHANISMS OF SINANODONTA WOODIANA EXPOSED TO MICROCYSTIN

Other Link： https://www.jstage.jst.go.jp/browse/journalofjsce/3/0/_contents

Language：English   Publishing type：Research paper (scientific journal)  

Antioxidant Responses of Vallisneria asiatica to Eutrophic Sediments in Lake Taihu, China

DOI： http://dx.doi.org/10.1007/s00128-015-1579-4

Other Link： http://link.springer.com/article/10.1007%2Fs00128-015-1579-4#page-1

Language：English   Publishing type：Research paper (scientific journal)  

In a 10-day aquarium experiment, this investigation examines macrophyte restoration in eutrophic Lake Taihu, the physiological effects of different plant biomass levels and of increasing natural cyanobacterial concentrations on a submerged macrophyte, Vallisneria asiatica. Cyanobacterial stress suppressed the superoxide dismutase (SOD) activity of the plant’s leaves and induced the catalase (CAT) and peroxidase (POD) activities of its roots. The soluble protein content in V. asiatica decreased with an increase in natural cyanobacterial concentrations, whereas the malonaldehyde (MDA) increased significantly at Chl.a concentrations of 222 and 262 µg·L−1 in water. V. asiatica adapted to the stress caused by cyanobacterial concentrations by adjusting its antioxidant defense system to remove the excessive reactive oxygen species when the algal Chl.a concentration was >109 µg·L−1. Additionally, high biomass of V. asiatica (2,222 g FW·m-2) can inhibit the reproduction of cyanobacteria more significantly than low biomass (1111 g FW·m-2). High biomass of V. asiatica increased the oxidative stress in an individual plant when the initial Chl.a concentration in the water reached 222 and 262 µg·L−1, as expressed by the increased MDA in leaves, compared with low biomass of V. asiatica. This provides a basis for controlling cyanobacterial concentrations and V. asiatica biomass for the recovery of V. asiatica in eutrophic Lake Taihu.

DOI： 10.1007/s00343-015-4084-z

Language：English   Publishing type：Research paper (scientific journal)  

Phosphorus is a necessary nutrient element to all lives in the world. Distribution and phosphate rock reserves in the world disclose shortage crisis of phosphorus. Thus phosphorus recovery has been a research hot spot in the world. Mr.Ohtake’ group [1] recommended a new method to recover phosphorus from sewage sludge during heating process. It seems that nearly 90% of the poly-phosphate (poly-P) and 87% of total phosphate (T-P) can be released from cultivated sludge by heating at 70˚C for 1 hour. Meanwhile, released poly-P can precipitate with Ca in neutral condition without any pH adjustment. Sewage sludge was used in this research to identify its performance during thermal treatment. With the increase of temperature and heating time, release of poly-P and T-P increased obviously. However, poly-P would be hydrolyzed when temperature was higher than 80 ˚C. With addition of EDTA, release of poly-P increased nearly 100%. Migration of metal cations during thermal treatment can provide indirect evidence which kinds of metal cations would make impediment on poly-P release. A novel phenomenon was observed poly-P mixed with ortho-phosphate can precipitate with NH4+ and Mg2+ as struvite at pH 8.5.

Other Link： http://www.ttp.net/978-3-03835-476-5/6.html

Language：Japanese   Publishing type：Research paper (other academic)  

近年、湖沼等の閉鎖性水域では富栄養化によるアオコ（主に藍藻類のMicrocystis属）の大量発生が深刻な問題となっている。これに対処するために、さまざまなアオコ防除法が実施されているが、流域社会構造の問題等から対応が進捗せず、アオコ防除施設の設置や運用には多くの費用を要する等の問題を抱えている。今日の社会情勢より省エネルギーで持続性があり、水域環境の改善にも効果のある対策が求められている。そこで、本研究では、Microcystis属と競合関係にある珪藻1)を活性化させてMicrocystis属の増殖を抑制することを目的として、ケイ酸供給による室内実験及び現場実験を行い、Microcystis属の生態工学的防除方法の有効性を検討した。

Language：English   Publishing type：Research paper (international conference proceedings)  

Phosphorus is a necessary nutrient element to all lives in the world. Distribution and phosphate rock reserves in the world disclose shortage crisis of phosphorus. Thus phosphorus recovery has been a research hot spot in the world. Mr.Ohtake’ group [1] recommended a new method to recover phosphorus from sewage sludge during heating process. It seems that nearly 90% of the poly-phosphate (poly-P) and 87% of total phosphate (T-P) can be released from cultivated sludge by heating at 70˚C for 1 hour. Meanwhile, released poly-P can precipitate with Ca in neutral condition without any pH adjustment. Sewage sludge was used in this research to identify its performance during thermal treatment. With the increase of temperature and heating time, release of poly-P and T-P increased obviously. However, poly-P would be hydrolyzed when temperature was higher than 80 ˚C. With addition of EDTA, release of poly-P increased nearly 100%. Migration of metal cations during thermal treatment can provide indirect evidence which kinds of metal cations would make impediment on poly-P release. A novel phenomenon was observed poly-P mixed with ortho-phosphate can precipitate with NH4+ and Mg2+ as struvite at pH 8.5.

Language：English   Publishing type：Research paper (scientific journal)  

To clarify the mechanism of submerged macrophytes disappearance and supply the necessary theory for the phytoremediation in eutrophic Lake Taihu, effects of the moderate nutrients concentration, high NH4+-N concentration and high PO43--P concentration in the water column on the antioxidant defense system in submerged macrophyte, Vallisneria asiatica, were studied with the 20-day aquarium experiments. The results showed that the moderate concentration of nutrients can promote the metabolism of V. asiatica. Either high concentrations of NH4+-N or PO43--P could cause the oxidative stress to cells of V. asiatica, expressed as decreased contents of chlorophyll a (Chl.a) and protein, and the enhancement of catalase (CAT) activities in leaves of V. asiatica. In addition, 0.6 mg·L-1 of PO43--P caused more oxidative damages to V. asiatica than 3.5 mg·L-1 NH4+-N. The results indicated that the antioxidative protection mechanisms could be activated but still could not prevent the damage of the metabolism system in V. asiatica exposed to either high concentrations of NH4+-N or PO43--P. Therefore, it is necessary to establish a dual control strategy of N and P for the restoration of V. asiatica in eutrophic Lake Taihu.

Language：English   Publishing type：Research paper (scientific journal)  

The purpose of this study was aimed at identifying the influence of metal cations such as Mg2+, Ca2+, Al3+ and Fe3+ on poly-phosphate (poly-P) and total phosphate (T-P) release from sewage sludge collected from wastewater treatment plant during thermal treatment at 70 degrees C for 80 min. With the addition of chelating reagent such as EDTA, release of poly-P and T-P was improved obviously during thermal treatment. Inhibitory effect of metal cations on phosphorus release was apparent by adding metal cations into sludge sample. Most of Ca, Al and Fe inside of cell could be released into the supernatant, but captured in extracellular polymeric substance (EPS); oppositely, large quantity of Mg could be released into the supernatant directly and not concentrated in EPS. Performance of sewage sludge on phosphorus release in summer and winter was different; different precipitation and temperature possibly result in this phenomenon.

Other Link： http://www.tandfonline.com/doi/pdf/10.1080/09593330.2013.863980

Language：English   Publishing type：Research paper (scientific journal)  

The bivalve Anodonta woodiana is widely distributed throughout Chinese freshwaters and is an important economic pearl mollusk. Recently, A. woodiana as a biomanipulation tool in Chinese lakes due to its strong suppression of phytoplankton, has been attracted increasingly more attention. In order to examine whether A. woodiana can exert grazing pressure on Microcystis and to evaluate the different effects of each algae diets on mussels’ potential growth, a comparative study was carried out on the acute physiological responses to variable microalgae diets including toxic MC-producing cyanobacteria and non-toxic Scenedesmus obliquus green algae. The values of filtration rate, absorption efficiency, oxygen consumption rate and ammonia excretion rate of A. woodiana were measured and finally the SFG (scope for growth) value as a measure of metabolic energy balance for A. woodiana was calculated and compared. The results showed that the mussel A. woodiana has a higher grazing ability on the toxic Microcystis aeruginosa compared with the green algae S. obliquus; Furthermore, the effects of different algae diets on SFG of A. woodiana demonstrated that the toxic M. aeruginosa may supply more energy for A. woodiana’s potential growth. These results indicated that A. woodiana has strong adaptation ability when they were exposed to toxic Microcystis solution in this study, which implied that there is high application feasibility of A. woodiana as a toxic Microcystis-blooming controller in practice.

Language：English   Publishing type：Research paper (scientific journal)  

To improve the water quality of lakes and control algae
blooms, the effects of Vallisneria asiatica which is one of aquatic
plants spread over Lake Taihu, with different biomasses on the water
quality and algae communities were researched. The results indicated
that V. asiatica could control an excess of Microcystis spp. when the V.
asiatica biomass was larger than 50g in the tank with 30L solution in
the laboratory. Planktonic and epiphytic algae responded differently to
V. asiatica. The presence of macrophyte V. asiatica in eutrophic
waters has a positive effect on algae compositions because of different
sensitivities of algae species to allelopathic substances released by
macrophyte V. asiatica. That is, V. asiatica could inhibit the growth of
Microcystis spp. effectively and was benefited to the diatom on the
condition in the laboratory.

Other Link： International Science Index 84, 2013 waset.org/publications/9996845

Language：English   Publishing type：Research paper (scientific journal)  

The bivalve is widely distributed throughout Chinese freshwaters and is an important economic pearl mollusk. Recently, Sinanodonta woodiana as a tool in biomanipulation of lakes in China due to its strong suppression of phytoplankton, has been attracted increasingly more attention. In order to evaluate the application feasibility of Sinanodonta woodiana as a Microcystis-blooming removal tool, microcosm experiments were performed with naturally blooming pond water and the bivalves in laboratory for 6 days. In this experiment, phytoplankton abundances and community structure were analyzed on 0-day and 6-day for both control and treatment microcosms; also, filtration rate, absorption efficiency, oxygen consumption rate and ammonia excretion rate of S. woodiana were measured on the 0-day and 6-day and finally the scope for growth (SFG) value as a measure of metabolic energy balance for S. woodiana was calculated and compared. The results showed that Microcystis spp. of colony and unicell were reduced obviously on the 6-day; meanwhile, after six days’ exposure to Microcystis-blooming pond water, the SFG value as a measure of metabolic energy balance for S. woodiana increased. This phenomenon indicates that Microcystis spp. in natural eutrophic water can be removed greatly by S. woodiana; moreover, the bivalves themselves have strong adaptation ability when they were exposed to natural eutrophic water and could grow well after 6 days’ exposure to this eutrophic water. Therefore, it can be inferred that there is high application feasibility of S. woodiana as a Microcystis-blooming controller in practice.

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

DISTRIBUTION CHARACTERISTICS OF WATER QUALITY AND AQUATIC VEGETATION IN A EUTROPHIC SHALLOW LAKE: TAIHU, CHINA

In order to find practical strategy for controlling eutrophication in Lake Taihu, in this study, water quality and biota were investigated in East Lake Taihu, Meiliang Bay and West Lakeshore. Compared with the lower nutrients concentrations in East Lake Taihu, the values of Chl.a, turbidity, T-N and T-P showed significant fluctuations with eutrophication level in different places of Meiliang Bay and West Lakeshore. There was significant positive correlation among each value of Chl.a, T-N and T-P in Meiliang Bay, which indicated that the occurrence of water bloom was related to the concentration of nutrient. According to the result of identification, there were totally twelve species of aquatic macrophytes in the investigated area, of which two species were found in Meiliang Bay, one species was found in the southwest coastal zone, and twelve species were found in East Lake Taihu including six species as dominant submerged plants. There were ten species of Cyanophyta during the water bloom in East Lake Taihu and Meiliang Bay, of which Microcystis aeruginosa was found with large quantities of biomass as dominant species. Apart from the Cyannophyta, 21 species of diatom and 20 species of Chlorophyta were identified in East Lake Taihu and Meiliang Bay, of which 41 species were spread in East Lake Taihu. The relatively richer phytoplankton indicated the higher biodiversity conditions in East Lake Taihu.

Language：English   Publishing type：Research paper (scientific journal)  

Because of the shortage crisis of phosphorus element and environmental problems caused by excess discharge of phosphorus compounds into nature water bodies, phosphorus recovery had been research hotspot. Poly-phosphate (poly-P) released from sewage sludge after thermal treatment could be recovered successfully as magnesium ammonium phosphate hexahydrate (MgNH4PO4•6H2O) commonly known as struvite in present study. This phenomenon was the first time to be found in phosphorus recovery from sewage sludge. The parameters affected struvite formation with poly-P had been tested. Poly-P indicated better characteristics in phosphorus recovery compared with ortho-phosphate (Pi) because it can be precipitated at lower pH condition even neutral condition, with less addition of magnesium element.

DOI： 10.4028

Language：English   Publishing type：Research paper (scientific journal)  

DOI： Article ID 838176

Language：English   Publishing type：Research paper (scientific journal)  

Extraction of Poly-Phosphate from the Activated Sludge with Thermal Treatment for Phosphorus Recovery

Language：English   Publishing type：Research paper (international conference proceedings)  

In situ Remediation of Contaminated Water of Crab Culture by Ecological Dam in Yang Cheng Lake

Language：English   Publishing type：Research paper (international conference proceedings)  

Improvement of Water Quality in Lake Taihu with Aquatic Plants and the Relationship between Cyanobacteria Bloom and Aquatic Plants

Language：English   Publishing type：Research paper (international conference proceedings)  

Improvement of Water Quality in Lake Taihu with Aquatic Plants and the Relationship between Cyanobacteria Bloom and Aquatic Plants

Language：Japanese   Publishing type：Research paper (scientific journal)  

Influence of Copper Ion on Antioxidant Function of Vallisneria asiatica

Language：English   Publishing type：Research paper (international conference proceedings)  

PRELIMINARY STUDY ON ECOLOGICAL ENGINEERING METHODS OF WATER QUALITY IMPROVEMENT IN THE LAKE TAIHU

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Phosphorus Removal Ability Intensified by Calcium Silicate Hydrates (CSH) in Ecological Technologies

Language：English   Publishing type：Research paper (international conference proceedings)  

THE EFFECT OF CHELATING REAGENTS ON THE RELEASE OF PHOSPHORUS FROM SEWAGE SLUDGE DURING HEATING PROCESS

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Language：English   Publishing type：Research paper (other academic)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Effect of Extended Feeding Time on Aerobic Granulation in SBR

Language：English   Publishing type：Research paper (scientific journal)  

Optimization of Internal Bypass Ratio for Complete Ammonium and Phosphorus Removal in a Dephanox-type Two-Sludge Denitrification System

Language：English   Publishing type：Research paper (scientific journal)  

A Comparative Study on Aerobic Granular Sludge and Effluent Suspended Solids in a Sequence Batch Reactor

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese  

Language：Japanese   Publishing type：Research paper (other academic)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Education and Learning Improvement by Introduction of an Evaluation System to Graduation Research

Language：English   Publishing type：Research paper (scientific journal)  

Effect of Rotifers on the Stability of Aerobic Granules

Language：English   Publishing type：Research paper (scientific journal)  

Effect of Anaerobic SRT on Complete Phosphate Removal in a Post-denitrification System

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Language：English   Publishing type：Research paper (international conference proceedings)  

Comparison of Nutrient Removal Efficiency between Pre- and Post-denitrification Wastewater Treatment

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Aerobic Granular Sludge: A Promising Technology for Decentralized Wastewater Treatment

Language：English   Publishing type：Research paper (scientific journal)  

Effect of Particulate Biodegradable COD in a Post-denitrification Enhanced Biological Phosphorus Removal System

Language：Japanese   Publishing type：Research paper (other academic)  

Education and Learning Improvement by Introduction of an Evaluation System to Graduation Research

Language：English   Publishing type：Research paper (scientific journal)  

The Influence of Starvation Phase on the Properties and the Development of Aerobic Granules

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Selective Force and Mature Phase Affect the Stability of Aerobic Granule: An Experimental Study by Applying Different Removal Methods of Sludge

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Activities of Enhanced Biological Nutrient Removal by the UCT Process in Low-Temperature Terms

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Recycling Technology of Water -Biological Sewage Treatment and Prevention of Eutrophication-

Language：English   Publishing type：Research paper (scientific journal)  

Promoting Nitrification by Using Functional Gel as Immobilizing Medium under Different Temperature Stimulation Patterns

DOI： 10.1081/ESE-120037877

Language：Japanese   Publishing type：Research paper (scientific journal)  

Isolation of the Denitrifying Phosphate-Accumulating Organisms Using Alternating Anaerobic-Anoxic Screening Method

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Language：English   Publishing type：Research paper (international conference proceedings)  

Development of an Activated Sludge Model with Denitrifying Dephosphatation

(第3回IWA国際水質会議, Melbourne Convention Centre, 2002)
( No.e211335a, pp.1-8, Enviro 2002 & IWA 3rd World Water Congress,
Australlia, 7-12 April, 2002

Language：Japanese   Publishing type：Research paper (other academic)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Application of Light-Stimulus-Responsive Gells to Immobilized Media

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Biological Dephosphatation by Activated Sludge under Denitrifying Conditions: pH Influence and Occurrence of Denitrifying Dephosphatation in a Full-scale Waste Water Treatment Plant

DOI： 10.1016/S0273-1223(97)00713-0

Language：English   Publishing type：Research paper (scientific journal)  

Biotechnology and Bioengineering, Vol.54, No.5, pp.434-450, 1997 Jun.

Language：English   Publishing type：Research paper (international conference proceedings)  

Increase in Rate of Biological Nitrification with NIPAAm Gel as Immobilizing Media

Language：English   Publishing type：Research paper (scientific journal)  

Kinetics and Stoichiometry in the Biological Phosphorus Removal Process with Short Cycle Times

Language：English  

Occurrence of Denitrifying Phosphorus Removing Bacteria in Modified UCT-type Waste Water Treatment Plants

Language：English   Publishing type：Research paper (scientific journal)  

A Sludge Characterization Assay for Aerobic and Denitrifying Phosphorus Removing Sludge

Language：English   Publishing type：Research paper (scientific journal)  

Metabolism of Micro-organisms Responsible for Enhanced Biological Phosphorus Removal from Wastewater: Use of Dynamic Enrichment Cultures

Language：English   Publishing type：Research paper (scientific journal)  

Environmental Impacts of Nutrient Removal Process: Case Study

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Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Biological Phosphorus Removal from Wastewater by Anaerobic-Anoxic Sequencing Batch Reactor

Language：Others   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/0043-1354(90)90155-Y

Language：English   Publishing type：Research paper (scientific journal)  

Transient Responses of Wastewater Treatment and Biomass Developement in a Methanogenic Fluidized Bed

Language：Japanese   Publishing type：Research paper (scientific journal)  

Evaluation of Methanogenic Activity Test using Glass Vials

Language：Japanese   Publishing type：Research paper (scientific journal)  

An Estimation Method of Active Biomass Concentration of Acetate utilizing Methanogen in Anaerobic Mixed Cultures

Language：Japanese   Publishing type：Research paper (scientific journal)  

Characteristcs of Volatile Fatty Acid Decomposition in Anaerobic Fluidized Bed

Language：Japanese   Publishing type：Research paper (scientific journal)  

Publisher：Separation and Purification Technology  

Effective radioactive wastewater treatment technology is essential to ensure the sustainable development of nuclear energy. Here, the potassium ferrocyanide (HCF) intercalating with layered double hydroxide (LDH) (HCF@LDH) was successfully synthesized by coprecipitation method for selective cesium (Cs) removal from seawater. Characteristics of the adsorbent, and adsorption performance under different environmental conditions including Cs+ ion selectivity, and underlying adsorption mechanism were systematically investigated. The experimental results demonstrated that the adsorption capacity of HCF@LDH was 52.08 mg/g and it effectively removed 100 % of Cs+ from up to 200 mg/L Cs solution within 1 h under an optimal pH of 6.0–10.0. Moreover, the adsorbent displayed high selectivity towards Cs+ even in seawater and more than 90 % of Cs+ was removed from seawater and the highest cesium removal capacity from seawater was 44.64 mg/g. Both the Langmuir isotherm model (R2 = 0.997) and the pseudo-second-order kinetic model (R2 = 0.999) provided a good fit for the adsorption data signifying the adsorption process is homogeneous and formed monolayer through chemisorption. Furthermore, the reusability analysis exhibited this adsorbent was recycled and reused for at least 5 cycles without losing its original adsorption performance. The physicochemical analysis of the HCF@LDH proved that K4Fe (CN)6 successfully intercalated onto LDH and cation exchange between K+ and Cs+ played an important role in effective Cs adsorption. More specifically, the interstitial spaces of the hexacyanoferrate crystals facilitate the cation exchange process. The findings of this study demonstrate that HCF@LDH is a unique, highly effective, and selective adsorbent for Cs+ from complex seawater.

DOI： 10.1016/j.seppur.2024.128984

Web of Science

Scopus

Publisher：Optik  

The photocatalytic degradation technique is one of the suitable ways of dealing with environmental pollutant decontamination. This study demonstrates the ability of graphitic carbon nitride (g-C3N4) nanocomposites containing tellurium (Te) and molybdenum disulfide (MoS2) to photocatalytically destroy organic cationic methylene blue (MB) dye, which is primarily used in the textile industry. Using the alkali treatment approach, layered graphitic carbon nitride (g-C3N4) was created. Using MoS2 and Te, several g-C3N4 nanocomposites were created using ultrasonic calcination techniques. After the MoS2 and Te were immobilized individually, the composites underwent a methodical characterization process utilizing a variety of instruments, including XRD and SEM. Using a 2D layered nano-g-C3N4 substrate, the photo-catalytic degradation reaction of MB was observed, and a UV spectrophotometer was used to determine the absorbance of the MB dye. Using 0.2 % MoS2/g-C3N4 and 5 % Te/g-C3N4, the photocatalytic degradation efficiency of the MB dye (10, 15, and 20 mg/L) solution was examined. In comparison to other produced nanocomposites, the 5 % Te/g-C3N4 composite was shown to have the highest photocatalytic activity in terms of dye degradation ability, and about 100 % of the MB dyes were degraded in less than 60 minutes. As the concentration of MB increased, the dye degradation efficiency of g-C3N4 nanocomposites steadily dropped, and the degradation rate of MB was around 1.5 mg/L.

DOI： 10.1016/j.ijleo.2024.171959

Scopus

Language：English   Publishing type：Research paper (scientific journal)  

The surface chemistry and the structural properties of activated carbon can be altered by the acidic modification. The objective of this study is to investigate the changes occurring in bamboo charcoal (BC) during activation with concentrated nitric acid. Low temperature (500^°C) carbonized BC has been prepared and oxidized with 70% concentrated boiling nitric acid (BC-AC). The porous properties of the BC are analyzed with nitrogen adsorption isotherm at 77 K. The surface structure is observed by Field emission scanning electronic microscope (FESEM) and the surface functional groups are examined by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and the pH of the point of zero charge (pH_PZC). The results reveal that severe oxidation with HNO₃ considerably decreases the surface area of BC with enhanced pore widening and FESEM observation demonstrates the erosive effect of oxidation. The FTIR analysis detects that some absorption bands are assigned for carboxyl, aldehyde and ketone groups on BC-AC. The XPS analysis also clearly shows that the ratio of oxygen and acidic functional groups has been enriched significantly on the BC-AC. The low pH_PZC value of BC-AC confirms that the surface is highly acidic for the fixation of acidic functional groups on surface. In general, the existence of the abundant amount of acidic functional groups on adsorbents enhances the sorption of heavy metals ions in aqueous solution. Therefore, it is strongly expected that the modified BC, activated under the proposed conditions would be a promising ion exchanger in aqueous solution and can be applied for the adsorption of different heavy metal ions and radioactive materials from effluent.

DOI： 10.1088/1755-1315/82/1/012002

Language：English   Publishing type：Research paper (scientific journal)  

The study is conducted to explore the potential of bamboo charcoal (BC) as an adsorbent to remove cesium from aqueous solution. Low temperature carbonized BC (500 °C) is prepared and the surface of the BC is modified with 70% concentrated boiling nitric acid (BC-AC). Specific surface area, field emission scanning electron microscope (FESEM), fourier transform infra-red (FTIR) spectroscopy, and point of zero charge (pH_pzc) of BC and BC-AC have been investigated in this study. The results demonstrate that BC-AC is enriched with oxygen-containing functional groups but its porous structure and surface area are decreased when compared with the raw BC. Optimum cesium adsorption conditions onto BC and BC-AC have been determined by investigating the contact time, pH of solution, adsorbent dosage and initial solution concentration in batch adsorption process. It has been observed that maximum cesium adsorption capacity is 0.17 and 45.87 mg/g for BC and BC-AC, respectively. It has also been observed that almost 100% cesium could be removed from water at up to 400 mg/L concentrated cesium solution by BC-AC whereas the removal capacity of cesium by BC is very poor. The experimental adsorption data of both BC and BC-AC follows the pseudo-second-order kinetic. The Freundlich adsorption equilibrium isotherm data is more appropriate than the Langmuir isotherm for adsorption of cesium by BC. However, adsorption isotherm data for BC-AC is a better fit with Langmuir isotherm than the Freundlich isotherm model. Furthermore, the separations factor (R_L) and the surface coverage (θ) for Langmuir isotherm confirms that the proposed adsorption process is the most suitable for BC-AC. This study suggests that BC-AC could be effectively used for the removal of cesium from environmental water.

DOI： 10.1016/j.jece.2017.02.014

Language：English   Publishing type：Research paper (scientific journal)  

Abstract Three kinds of representative sediments were obtained from a macrophyte-dominated bay (East Lake Taihu) and two algae-dominated regions (Western Lake Taihu and Meiliang Bay). Physiological responses of Vallisneria asiatica to these sediments were compared. Results from 20 days exposures showed no obvious differences in malondialdehyde (MDA) in roots, while the MDA content in leaves of plants exposed to Western Lake Taihu sediment was significantly (p < 0.05) higher than those exposed to the other two sediments. In comparison to the other two sediments, plants exposed to Western Lake Taihu sediment showed significantly lower (p < 0.05) superoxide dismutase in roots and leaves on the 10th and 40th day. On the 40th day, root catalase (CAT) activities in V. asiatica from Western Lake Taihu and Meiliang Bay sediments were lower than that from East Lake Taihu sediment, while leaf CAT activity in V. asiatica from Western Lake Taihu sediment was higher than that from East Lake Taihu sediment (p < 0.05). Western Lake Taihu sediment caused more serious oxidative stress in V. asiatica than East Lake Taihu sediment. Results indicated eutrophic sediment was a contributing factor in the disappearance of V. asiatica in Western Lake Taihu.

DOI： 10.1007/s00128-015-1579-4

Language：Japanese   Publishing type：Research paper (scientific journal)  

POLYPHOSPHATE RECOVERY FROM SEWAGE SLUDGE AS MAGNESIUM AMMONIUM PHOSPHATE AND ITS FORMING ABILITY

DOI： 10.2208/jscejer.71.III_107

Language：English   Publishing type：Research paper (scientific journal)  

The purpose of this study was aimed at identifying the influence of metal cations such as ^Mg2+, Ca²⁺, Al³⁺ and Fe ³⁺ on poly-phosphate (poly-P) and total phosphate (T-P) release from sewage sludge collected from wastewater treatment plant during thermal treatment at 70°C for 80 min. With the addition of chelating reagent such as EDTA, release of poly-P and T-P was improved obviously during thermal treatment. Inhibitory effect of metal cations on phosphorus release was apparent by adding metal cations into sludge sample. Most of Ca, Al and Fe inside of cell could be released into the supernatant, but captured in extracellular polymeric substance (EPS); oppositely, large quantity of Mg could be released into the supernatant directly and not concentrated in EPS. Performance of sewage sludge on phosphorus release in summer and winter was different; different precipitation and temperature possibly result in this phenomenon.

DOI： 10.1080/09593330.2013.863980

Language：Japanese   Publishing type：Research paper (scientific journal)  

Metabolic and Antioxidant Responses of Vallisneria asiatica to Different Concentrations of Dissolved Inorganic Nitrogen and Phosphorus

DOI： 10.2521/jswtb.50.105

Language：English   Publishing type：Research paper (other academic)  

Because of the shortage crisis of phosphorus element and environmental problems caused by excess discharge of phosphorus compounds into nature water bodies, phosphorus recovery had been research hotspot. Poly-phosphate (poly-P) released from sewage sludge after thermal treatment could be recovered successfully as magnesium ammonium phosphate hexahydrate (MgNH₄PO₄·6H₂O) commonly known as struvite in present study. This phenomenon was the first time to be found in phosphorus recovery from sewage sludge. The parameters affected struvite formation with poly-P had been tested. Poly-P indicated better characteristics in phosphorus recovery compared with ortho-phosphate (Pi) because it can be precipitated at lower pH condition even neutral condition, with less addition of magnesium element.

DOI： 10.4028/www.scientific.net/AMR.781-784.1963

Language：English   Publishing type：Research paper (other academic)  

Fast consumption of high quality phosphorus mines and uneven distribution in the world result in the shortage crisis for phosphorus, meanwhile lots of phosphate compounds which are discharged into nature water bodies by human beings have already induced many environmental problems. Because of this situation, phosphorus recovery from sewage sludge working in the aeration tank of wastewater treatment plant (WWTP) has been researched in the present study. Poly-phosphate (poly-P) and total phosphate (T-P) accumulated inside activated sludge could be released by thermal treatment at low temperature, 30% poly-P and 29% T-P could be released from sludge by heating at 70 °C. Different kinds of pretreatments had been tested to improve phosphorus release from activated sludge in thermal treatment; addition of chelating reagent at final concentration of 2 mM before thermal treatment could improve the phosphorus release obviously, 68% poly-P and 53% T-P could be released into liquid phase. Approximately 85% T-P could be precipitated with calcium at pH 11; it was interesting to find precipitation occurred in neutral condition without pH adjustment.

DOI： 10.4028/www.scientific.net/AMR.610-613.2268

Language：English   Publishing type：Research paper (scientific journal)  

The occurrence and distribution of microcystins were investigated in Lake Taihu, the third largest lake in China. An extensive survey, larger and broader in scale than previous studies, was conducted in summer 2010. The highest microcystin concentration was found at southern part of Taihu, which was newly included in this survey. In northern coastal areas, total cellular concentrations of 20 to 44 g/L were observed. In northern offshore waters, levels were up to 4.8 g/L. Microcystin occurrence was highly correlated with chemical oxygen demand, turbidity, and chlorophyll-a. Extracellular/total cellular microcystin (E/T) ratios were calculated and compared to other water quality parameters. A higher correlation was found using E/T ratios than original microcystin values. These results show that algal blooms are having a severe impact on Lake Taihu, and further and extensive monitoring and research are required to suppress blooms effectively.

DOI： 10.1155/2013/838176

Language：Japanese   Publishing type：Research paper (scientific journal)  

DISTRIBUTION CHARACTERISTICS OF WATER QUALITY AND AQUATIC VEGETATION IN A EUTROPHIC SHALLOW LAKE

DOI： 10.2208/jscejer.69.97

Language：English   Publishing type：Research paper (scientific journal)  

 Sinanodonta woodiana is widely distributed throughout Chinese freshwaters and is an important economic pearl mollusk. In order to evaluate the application feasibility of S. woodiana as a Microcystis-blooming removal tool, a series of microcosm experiments were performed. First the 6-day feeding responses experiment was carried out with naturally blooming pond water and the bivalves in laboratory, which was lasted for 6 days. In this experiment, phytoplankton abundances and community structure were analyzed on 0-day and 6-day for both control and treatment microcosms; also, filtration rate, absorption efficiency, oxygen consumption rate and ammonia excretion rate of S. woodiana were measured on 0-day and 6-day and finally the scope for growth (SFG) value as a measure of metabolic energy balance for S. woodiana was calculated and compared. The results showed that Microcystis spp. of colony and unicell were reduced obviously on the 6-day; meanwhile, after six day's exposure to Microcystis-blooming pond water, the SFG value for S. woodiana increased. Furthermore, in the extended long-term grazing experiment, bivalves were fed with highly concentrated toxic Microcystis-blooming water and non-toxic Chlorella at the constant concentration (Chl.a=424.5 mg/m³) in two respective tanks for 12 days. No bivalve mortality was registered on both Chlorella group and blooming water group. In addition, SFGs were significantly higher for the blooming water group, compared with them for Chlorella group on 3-day, 6-day and 12-day. These results indicated that toxic Microcystis spp. in natural eutrophic water can be removed greatly by S. woodiana; moreover, the bivalves themselves have strong adaptation ability when they were exposed to toxic natural eutrophic water. Therefore, it can be inferred that there is high application feasibility of S. woodiana as a Microcystis-blooming controller in practice.

DOI： 10.2208/jscejer.69.III_45

Language：Japanese   Publishing type：Research paper (scientific journal)  

Effects of copper ion on antioxidant function of Vallisneria asiatica

DOI： 10.3825/ece.14.115

Language：English   Publishing type：Research paper (scientific journal)  

Cryosectioned granules were observed in microstructure, Extracellur Polymeric Substances (EPS) and metal distribution. Aerobic granules composed of pores and channels that were not plugged by EPS, with rather open structure. Microorganisms proliferated mainly on the surface of granule and on the wall of channels, carbohydrate EPS mainly distributed on the surface of granules, and protein EPS mainly distributed in the interior part of granules. Also, aerobic granules accumulated considerable calcium and phosphorus, which increase the ash solid fraction of granules and thus improve the settleability. Additionally, iron was neither temporally accumulated nor heterogeneously spatially distributed.

DOI： 10.1504/IJEP.2011.039082

Language：English   Publishing type：Research paper (scientific journal)  

The objective of this research is to demonstrate the antioxidant ecological response of Vallisneria asiatica to the heavy metal Cu²⁺ pollution which is recently a serious problem in the lakes. Batch experiments with five different concentrations of Cu²⁺ (0, 5, 10, 20, 40, 80 mg·L^-1) were carried out. After the 12th day, the roots and leaves of Vallisneria asiatica dipped in the solution with Cu²⁺ were removed and the physiological and biochemical indexes, chlorophyll, protein and malondialdehyde (MDA) content, superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activity were measured. After the experiment; the roots and leaves cultivated in the 0 mg·L^-1 of Cu²⁺ group showed chlorophyll and protein content reduced while the MDA content, POD and SOD activity were increased notoriously. Compared with the 0 mg·L ^-1 of Cu²⁺ group, the 5 mg·L^-1 of Cu²⁺ group showed chlorophyll and protein content increase, SOD and POD activity showed also a slight increase, while MDA content decreased. However, for the 10 mg·L^-1 of Cu²⁺ group, the decrease of chlorophyll and protein content and the increase of MDA content were observed. Also a sharp increase of SOD and CAT activity compared with the 5 mg·L^-1 group were found; for over 10 mg·L^-1 of Cu²⁺ concentration, chlorophyll content and protein content fell off, whereas increase of MDA became considerable, CAT raised up steadily and POD showed a decrease trend. The results showed that, both insufficiency and overabundance of Cu²⁺ in water environment can affect the anti-oxidation function of Vallisneria asiatica, which can be observed by the value of SOD, CAT and POD activity. Therefore, the measurement of anti-oxidation activity, protein content and MDA as a forecast and judgment indicator of Cu²⁺ contaminations in the water environment can be considered in the future.

DOI： 10.3825/ece.14.115

Language：Japanese   Publishing type：Research paper (scientific journal)  

Capacity and Mechanism of Nitrate Anion Adsorption onto Bamboo Charcoal

DOI： 10.2965/jswe.32.369

Language：English   Publishing type：Research paper (scientific journal)  

Two different feeding lengths were applied to control the granule size. It was found that the size of granules was considerably controlled in R2 (60 min for feeding). However, the settleability in R2 was not as good as that in R1 (12 min for feeding). However, this approach of controlling the granule size also loosens the structure concerning on the difference between SVI5 and SVI30, which might lead to instability in the long term. Based on the observation of the ash-solids fraction of biomass, it was confirmed that frequent update of granules mainly happened on the surface of granules.

DOI： 10.1504/WRSTSD.2009.031833

Language：English   Publishing type：Research paper (scientific journal)  

The capacity of complete simultaneous ammonium and phosphate removal was studied in a laboratory scale Dephanox system in relation to its internal bypass ratio (BPR). In this configuration, most of the ammonium detected in the effluent is ammonium bypassed by the system's internal settler. Therefore, this research studies the possibility of complete simultaneous ammonium and phosphate removal by means of the balance of bypassed ammonium with ammonium requirement for growth of denitrifying phosphorus accumulating organisms in the anoxic tank. During these experiments, ammonium removal was governed by internal BPR and limited by sludge settleability. The predominant anaerobic-anoxic sludge developed a high settleability, allowing the application of drastic low BPRs. The system studied under many BPRs proved to achieve almost complete simultaneous ammonium and phosphate removal for BPRs ranging from 0.08 to 0.13 of the influent. A BPR lower than the inferior limit produced extreme accumulation of sludge into the internal settler, interfering in the distribution of sludge and consequently in removal efficiency. A positive effect of the internal settler was the extension of anaerobic contact time and anaerobic solids retention time. The increased phosphorus release suggests that a higher volatile fatty acids production might have occurred when raw wastewater was used as influent.

DOI： 10.1061/(ASCE)0733-9372(2008)134:7(536)

Language：English   Publishing type：Research paper (scientific journal)  

Having outstanding settleability, aerobic granular sludge receives increasing attention for wastewater treatment. Washing out undesired sludge (frequently in the form of flocs) is an essential operation condition for developing granules, and thus a high solids concentration is in effluent. However, the properties of effluent solids have not been fully understood. To study the properties of effluent solids could better understand granulation and provide basic information for the followed polish unit design to remove these solids. Results in this study shows that sizes of effluent solids increased with the increase of granule size. The effluent solids exhibited higher EPS (extracellular polymer substances) concentrations but lower fraction of carbohydrate content, and higher fraction of ash solids. The properties of effluent suspended solids and deteriorated granules changed in a similar fashion, suggesting that the effluent solids resulted mainly from the deteriorated granules. It was also found that ash solids buildup was a result of compact structure, which in turn, improved the stability of granules by increasing the settleability.

DOI： 10.1089/ees.2007.0091

Language：Japanese   Publishing type：Research paper (scientific journal)  

Education and Learning Improvement by Introduction of an Evaluation System to Graduation Research Work

DOI： 10.4307/jsee.55.4_60

Language：English   Publishing type：Research paper (scientific journal)  

The current study evaluated the effect of rotifers on the stability of aerobic granules. Two sequence batch reactors (SBRs) with airflow rates of 4 (R1) and 6 (R2) l min^-1, respectively, were used to develop aerobic granules. Granules were well developed with excellent settleability in terms of SVI₃₀ (sludge volume index,) of about 50 ml g^-1 in both reactors at the beginning. With the outgrowth of rotifers, granules completely disintegrated in R1 around cycle 500 (a cycle was 3 hours). However, after the rotifers disappeared, i.e. cycle 550, granules re-appeared with a slow settling rate in R1 (SVI₃₀ : 200-300 ml g^-1). The rotifers mechanically damaged the structure of granules, resulting in disintegration. However, granules developed under high shear force seem to have strong resistance to rotffers. During re-granulation, a long time lag between the improvements of morphology and settleability suggested that re-granulation resulted from entanglement more than bio-attachment or bio-growth. Additionally, it was confirmed that the ratio of carbohydrate to protein extracellular polymeric substances (EPS) could well indicate the strength of granules. Protein EPS well correlated with the difference between SVI₅ and SVI₃₀ in R1, therefore, decreasing protein EPS would increase the compactness of granules.

DOI： 10.1080/09593332808618772

Language：English   Publishing type：Research paper (scientific journal)  

To evaluate the effect of sludge removal methods on the stability of aerobic granules, three different removal methods of sludge were investigated in sequencing batch reactors (SBR). Results demonstrated that (i) in R1, removing fresh granules effectively maintained granules with sizes of 1-2 mm and SVI of 31-45 ml g^-1 for more than 432 cycles (one cycle length was 3 h); (ii) in R3, removing aged granules led to disintegration of granules; (iii) in R2, removing completely mixed sludge resulted in granules with good settleability. However, the morphology of granules in R2 was similar to that of granules in R3 with sizes of about 4-5 mm. It was also found that removing fresh granules built up more ash solids in granules than removing aged granules did and removing aged granules significantly led to lysed granules with void shells. Results suggest that removing fresh granules is an effective approach of selective force for aerobic granulation, and the mature phase plays an important role on the stability of granules by rearranging granule structure (e.g. the buildup of ash solids).

DOI： 10.1016/j.enzmictec.2006.01.030

Language：English   Publishing type：Research paper (scientific journal)  

This research studied the effects of the particulate biodegradable fraction (X S ) of chemical oxygen demand (COD) in a post-denitrification configuration. Denitrifying polyphosphate-accumulating organisms (DN-PAOs) and nitrifiers were completely separated in a system also known as Dephanox. It was composed by an anaerobic-anoxic (A 2 ) process coupled with a parallel Nitrification biofilm tank. The results of a long-term operation of the Dephanox continuous-flow lab-scale system as well as results of sludge characterization assays showed that raw wastewater feeding promoted complete phosphorus (P) removal by double via (i) providing complementary volatile fatty acids (VFAs) for a complete P removal by prefermentation of the X S fraction of COD under a long anaerobic SRT, and (ii) assisting the metabolic accumulation and selection of DN-PAOs. Complete P removal was accomplished only when the system was fed with raw wastewater (high X S concentration). When primary effluent was used as influent, lack of VFAs in the anaerobic stage led to an incomplete and instable P removal, suggesting that the use of primary treatment is not only unnecessary but detrimental for simultaneous nutrient removal in a post-denitrification configuration.

DOI： 10.1080/10934520600754771

Language：English   Publishing type：Research paper (scientific journal)  

In order to evaluate the characteristics of aerobic granular sludge, a sequencing batch reactor, feeding with synthetic wastewater at the organic loading rate of 8 kg COD/m³ d, was employed on the laboratory scale. Granules occurred in the reactor within 1 week after the inoculation from conventional flocculent sludge. Aerobic granular sludge was characterised by the outstanding settling properties and considerable contaminates removal efficiencies. The SVI₃₀ values were in the range of 20 to 40 ml g^-1. However, the sludge volume index of short settling time (e.g. SVI₁₀ - 10 min) is suggested to describe the fast settling properties of aerobic granular sludge. The potential application in the decentralised system is evaluated from the point view of footprint and high bioactivity. The occurrence of sloughing, resulting from the outgrowth of filamentous organisms, would be responsible for the instability of aerobic granules. The starvation phase should therefore be carefully controlled for the maintenance and stability of aerobic granular sludge system.

DOI： 10.2166/wst.2006.278

Language：English   Publishing type：Research paper (scientific journal)  

A shortage of organic substances (COD) may cause problems for biological nutrient removal, that is, lower influent COD concentration leads to lower nutrient removal rates. Biological phosphorus removal and denitrification are reactions in which COD is indispensable. As for biological simultaneous nitrogen and phosphorus removal systems, a competition problem of COD utilisation between polyphosphate accumulating organisms (PAOs) and non-polyphosphate-accumulating denitrifiers is not avoided. From the viewpoint of effective utilisation of limited influent COD, denitrifying phosphorus-removing organisms (DN-PAOs) can be effective. In this study, DN-PAOs activities in modified UCT (pre-denitrification process) and DEPHANOX (post-denitrification ptocess) wastewater treatments were compared. In conclusion, the post-denitrification systems can use influent COD more effectively and have higher nutrient removal efficiencies than the conventional pre-denitrification systems.

DOI： 10.2166/wst.2006.272

Language：English   Publishing type：Research paper (scientific journal)  

The current study was to evaluate the influence of starvation phase on surface negative charge, relative hydrophobicity, extra-cellular polymer substances (EPS) and the formation mechanism of aerobic granules. Granules with encouraging settling properties occurred in the reactor about 7 days after the inoculation. The surface negative charge decreased from 0.203 to 0.023 meq g VSS^-1 and the relative hydrophobicity increased from 28.8 to 60.3% during the granulation period. Concentrations of protein and carbohydrate decreased from 18.0 to 7.1 and 7.0 to 2.9 mg g VSS^-1, respectively in the first period. And from day 13, those values were observed in the range of 5.8-8.6 and 2.9-5.6 mg g VSS^-1, respectively. The EPS especially protein concentrations well correlated with surface charge and relatively hydrophobicity. It was concluded that a reasonable amount of EPS should be controlled to form and maintain aerobic granules. It was proposed that aerobic granulation was initiated by starvation phase and then enhanced by anaerobic metabolism.

DOI： 10.1016/j.enzmictec.2005.07.020

Language：Japanese   Publishing type：Research paper (scientific journal)  

7-216 Education and Learning Improvement by Introduction of an Evaluation System to Graduation Research

DOI： 10.20549/jseejaarc.2006.0_416

Language：English   Publishing type：Research paper (scientific journal)  

A continuous flow post-denitrification (Dephanox type) lab-scale system fed with raw wastewater was operated in order to investigate the effect of the anaerobic solids retention time (anaerobic SRT) on phosphate removal. The presence of an internal settler just after the anaerobic tank enhanced the anaerobic SRT. Additional enhancement was provided by accumulation of solids into the internal settler under extreme operational conditions that seemed to be optimal for nutrients removal. Batch experiments with Dephanox sludge showed that the particulate COD fraction contributed with an additional 50% of phosphate release, thus an additional VFAs production can be inferred. In the case of the Dephanox sludge, the enhanced anaerobic SRT assisted effectively to achieve complete phosphate removal. As reference, the same batch experiments with AO and A₂O sludge from a full scale plant fed with primary effluent were carried out. The results showed that particulate COD fraction did not contribute significantly on the VFAs production. The combination of long SRT and abundant particulate COD apparently promoted fermentative organisms and denitrifying phosphorus accumulating organisms (DN-PAOs) acting in a syntrophic association on phosphorus removal.

DOI： 10.11532/proes1992.43.327

Language：Japanese   Publishing type：Research paper (scientific journal)  

ACTIVITIES OF ENHANCED BIOLOGICAL NUTRIENT REMOVAL BY THE UCT PROCESS IN LOW-TEMPERATURE TERMS

DOI： 10.2208/jscej.2005.783_61

Language：Japanese   Publishing type：Research paper (scientific journal)  

Isolation of the Denitrifying Phosphate-Accumulating Organisms Using Alternating Anaerobic-Anoxic Screening Method

DOI： 10.11532/proes1992.40.53

Language：Japanese   Publishing type：Research paper (scientific journal)  

Application of Light-Stimulus-Responsive NIPA-CH Gels to Immobilized Media

DOI： 10.2965/jswe.24.601

Language：Japanese   Publishing type：Research paper (scientific journal)  

A Possibility of Control and Prevention of Excessive Phytoplankton Growth by Photochromism

DOI： 10.2965/jswe.22.932

Language：English   Publishing type：Research paper (scientific journal)  

In this work, an integrated metabolic model for biological phosphorus removal is presented. Using a previously proposed mathematical model it was shown to be possible to describe the two known biological phosphorus removal processes, under aerobic and denitrifying conditions, with the same biochemical reactions, where only the difference in electron acceptor (oxygen and nitrate) is taken into account. Though, apart from the ATP/NADH ratio, the stoichiometry in those models is identical, different kinetic parameters were found. Therefore, a new kinetic structure is proposed that adequately describes phosphorus removal under denitrifying and aerobic conditions with the same kinetic equations and parameters. The ATP/NADH ratio (δ) is the only model parameter that is different for aerobic and denitrifying growth. With the new model, simulations of anaerobic/aerobic and anaerobic/denitrifying sequencing batch reactors (A₂ SBR and A/O SBR) were made for verification of the model. Not only short-term behavior, but also steady state, was simulated. The results showed very good agreement between model predictions and experimental results for a wide range of dynamic conditions and sludge retention times. Sensitivity analysis shows the influence of the model parameters and the feed substrate concentrations on both systems.

DOI： 10.1002/(SICI)1097-0290(19970605)54:5<434::AID-BIT4>3.0.CO;2-F

Language：English   Publishing type：Research paper (scientific journal)  

Aerobic or denitrifying biological phosphorus removal in a sequencing batch rector (SBR) with short repetitive anaerobic-aerobic (A/O) or anaerobic-anoxic (A2) cycling has been studied. These conditions resemble processes with large internal recycle flows. Under these conditions the fatty acid dosage per anaerobic phase is low compared to a conventional SBR or plug flow process. It was shown that at the same sludge retention time (SRT) the average poly-β-hydroxybutyrate (PHB) content of the biomass decreased, with increasing the number of A/O or A2 cycles. This had no direct effect on the biological phosphorus removal. In the A2 SBR, however, phosphorus removal was deteriorating due to transfer of nitrate to the anaerobic phase. Most mathematical models for biological phosphorus removal processes show a relation between the biomass growth rate and the PHB content. This research shows that such a unique relation does not exist, since at one SRT different `steady state' PHB levels could be obtained, depending on the cycle number and the use of oxygen or nitrate as an electron acceptor. This indicates the need for an alternative kinetic model.

DOI： 10.1016/S0043-1354(96)00371-5

Language：English   Publishing type：Research paper (scientific journal)  

The occurrence of denitrifying phosphorus removing bacteria (DPB) and the contribution of DPB to phosphorus removal in full-scale wastewater treatment plants (WWTPs) has been investigated by batch tests with the activated sludge from two WWTPs (WWTP-Genemuiden and -Holten). Both WWTPs are operated as UCT-type processes. Batch tests to evaluate the biomass composition of the sludges were developed. These batch tests showed a clear difference of denitrifying dephosphatation activity between the WWTP-Genemuiden and -Holten sludge. In the sludge of the WWTP-Genemuiden the (denitrifying) dephosphatation activity was rather low, whereas a high activity was formed in the WWTP-Holten sludge. The following possible reasons for the lower proportion of (denitrifying) dephosphatation activity in the WWTP-Genemuiden sludge in comparison with the WWTP-Holten sludge, were suggested; (a) nitrate/oxygen transfer to the anaerobic/anoxic zone due to the internal recirculation inside the treatment plant, (b) lower amounts of fatty acids in the influent due to shorter retention time of waste water in sewer lines, and (c) lower amount of nitrate recycled to the anoxic zone.

DOI： 10.1016/S0043-1354(96)00370-3

Language：English   Publishing type：Research paper (scientific journal)  

It was recently recognized that denitrifying bacteria, as well as aerobic bacteria, contribute to the biological phosphorus removal process. For evaluation of the phosphorus removal process it is necessary to have tests enabling a proper characterization of the microbial population in the activated sludge. In this study we evaluated the possibility of anoxic phosphorus release or aerobic/anoxic phosphorus uptake tests for sludge characterization. Hereto we employed sludge mixtures of enrichment cultures from laboratory sequencing batch reactor (SBR) systems operated under aanaerobic-aerobic (A/O) or anaerobic-anoxic (A2) conditions. It is shown that interpretation of phosphorus release tests, with or without nitrate present, is difficult. On the other hand a comparison of phosphorus uptake under aerobic and anoxic conditions leads to a straightforward characterization of the microbial population in the phosphorus removing organisms, with respect to their phosphorus removal activity under aerobic and anoxic conditions.

DOI： 10.1016/S0043-1354(96)00281-3

Language：English   Publishing type：Research paper (scientific journal)  

The influence of primary clarification of sewage on nitrogen and phosphorus removal in a modified University of Cape Town (UCT) type wastewater-treatment plant (WWTP) has been studied on a full scale. Before or after the introduction of raw sewage, the sludge was characterized on (denitrifying) phosphorusremoving activities by batch tests. For both situations, mass and energy balances in the WWTP were made in order to evaluate the effect of presettling on the environmental impact of the treatment process. Extra chemical oxygen demand (COD) input due to the introduction of raw sewage improved the overall nitrogen removal, whereas P-removal remained good. However, the improvement of nitrogen removal resulted mainly from increased assimilation into extra sludge production, not from increased denitrification. In fact, results of the batch tests indicated that the denitrification activity after the introduction of raw sewage was almost similar to the sludge with presettled sewage. The introduction of raw sewage resulted in an increase of energy consumption, mainly due to lower methane production in the digester. This research shows that evaluating treatment processes solely on effluent quality can easily lead to overall adverse effects for the environment. The full environmental impact should also be considered for treatment processes.

DOI： 10.1061/(asce)0733-9372(1997)123:1(33)

Language：English   Publishing type：Research paper (scientific journal)  

The removal of phosphorus from wastewater is already widely applied. In many cases use is made of micro organisms capable of accumulating phosphorus as polyphosphate inside the cell. The main characteristic providing the competitive advantage to these polyphosphate accumulating bacteria is the capability to use polyphosphate, in the absence of external electron accepters, as energy source for the uptake and storage of acetic acid in the form of polyhydroxybutyrate (PHB). The reduction equivalents for the formation of PHB are derived from the conversion of glycogen to PHB. Despite the widespread use and study of enhanced biological phosphorus removal no pure culture, having the above mentioned characteristics, has been isolated yet. All ecophysiological studies on these type of cultures have therefore been performed by enrichment cultures. This paper reviews the research on these type of organisms, and shows that it is possible to understand a complex microbial process on a metabolic level, both stoichiometrically and kinetically, without the availability of a pure culture.

DOI： 10.1023/A:1000150523030

Language：English   Publishing type：Research paper (scientific journal)  

A metabolic model for biological phosphorus removal under denitrifying conditions has been established. The model is based on previous work with aerobic phosphorus removal. The form of the kinetic equations used is the same as for the aerobic model. The main difference is the value of P/NADH₂ ratio in the electron transport phosphorylation with nitrate (δ(N)). This value was determined independently from batch tests with an enriched culture of denitrifying phosphorus-removing bacteria. The measured δ(N) was approximately 1.0 mol ATP/mol NADH₂. This indicates that the energy production efficiency with nitrate compared to oxygen is approximately 40% lower. These batch tests were also used to identify a proper set of kinetic parameters. The obtained model was subsequently applied for the simulation of cyclic behavior in an anaerobic-anoxic sequencing batch reactor at different biomass retention times. The simulation results showed that the metabolic model can be used successfully for the denitrifying dephosphatation process. The obtained kinetic parameters for denitrifying enrichment cultures, however, deviated from those obtained for the aerobic enrichment cultures.

DOI： 10.1002/(SICI)1097-0290(19961220)52:6<685::AID-BIT6>3.3.CO;2-M

Language：English   Publishing type：Research paper (scientific journal)  

Denitrifying dephosphatation enables the removal of phosphorus and nitrogen with minimal use of COD, minimal oxygen consumption and minimal surplus sludge production. Moreover it would make aeration only necessary for nitrification. Therefore we have studied an anaerobic-anoxic (A₂) sequencing batch reactor (SBR) coupled to a nitrification SBR. Denitrifying phosphorus removing bacteria (DPB) and nitrifiers were completely separated in two sludges in these two SBRs. The nitrified supernatant was recirculated from the nitrification SBR to the A₂ SBR where nitrate was utilized by DPB as an electron acceptor for phosphorus removal. The technical feasibility for simultaneous phosphorus and nitrogen removal in the proposed two-sludge system was evaluated. The benefits of two-sludge systems over single-sludge systems were also discussed. It could be concluded that the separation of the nitrification step leads to an optimal process design for the application of denitrifying dephosphatation. The two-sludge system showed stable phosphorus and nitrogen removal, and enabled the removal of 15 mg-P/1 and 105 mg N/1 at the expense of only 400 mg-COD/1 acetic acid. Stoichiometric calculations showed that, in the two-sludge system the required COD can be up to 50% less than for conventional aerobic phosphorus and nitrogen removal systems. Moreover oxygen requirements and sludge production can be decreased in significant amounts of about 30 and 50%, respectively.

DOI： 10.1016/0043-1354(96)00050-4

Language：English   Publishing type：Research paper (scientific journal)  

The effect of oxygen on the activity of denitrifying phosphorus removing bacteria has been studied. Denitrifying phosphorus removing bacteria were enriched without oxygen in an anaerobic-anoxic SBR (sequencing batch reactor) over a long time, after which an aerobic phase was introduced into the SBR. The performance on phosphorus and nitrogen removal was examined for an anaerobic-aerobic-anoxic SBR. It could be concluded that oxygen has no detrimental effect on the denitrifying dephosphatation activity. The maximum phosphorus uptake rate by the enriched denitrifying sludge was almost equal for anoxic and aerobic conditions, and the anoxic phosphorus removal activity was kept within at least 5 months after the introduction of the aerobic phase. From the experiments it followed that the advantage of applying denitrifying phosphorus removing bacteria can only be obtained in a pre-denitrification process like the UCT-type of process.

DOI： 10.1016/0273-1223(96)00492-1

Language：English   Publishing type：Research paper (scientific journal)  

The effect of nitrate on phosphorus release by biological phosphorus removing organisms has been studied. Denitrifying (PB) or aerobic phosphorus removing bacteria were enriched in an anaerobic-anoxic or anaerobic-aerobic sequencing batch reactor (SBR). The enrichment sludges were used in batch tests, in which the effect of simultaneous presence of substrate (HAc) and nitrate was studied on the phosphorus release. It could be concluded that a reduction of the phosphorus release by nitrate in biological phosphorus removal systems is partly due to the presence of DPB, which utilize HAc for denitrification, not for phosphorus release. PHB (poly-β-hydroxybutyrate) was always produced and phosphorus was released by DPB sludge when nitrate and HAc were simultaneously present. The reducing power (NADH₂) and the energy (ATP) for this process seemed to be obtained from HAc oxidation by nitrate as well as from polyphosphate degradation. After removal of the HAc, PHB degradation and phosphorus uptake occurred.

DOI： 10.2166/wst.1994.0277

Language：English   Publishing type：Research paper (scientific journal)  

In this study an anaerobic-anoxic SBR(sequencing batch reactor) was used in order to investigate the possibility of phosphorus removal process. Comparison of stoichiometry and kinetics with the conventional anaerobic-aerobic SBR system shows a similar potential for phosphorus removal by denitrifying organisms. Therefore in the design of phosphorus removal processes one should not be afraid of nitrate, but use it.

DOI： 10.2166/wst.1993.0504

Language：English   Publishing type：Research paper (other academic)  

The objectives of this study are to develop a model which can express the characteristics of anaerobic treatment in a methanogenic fluidized bed reactor in non-steady states, and evaluate the usefulness of the model in which 'active' biomass concentration is used as a index of bacteria concentration instead of traditional ones such as volatile suspended solids. The treatment in the fluidized bed reactor started with biocoated synthetic zeolite as support material. The reactor was supplied with synthetic wastewater, a mixture of volatile fatty acids. An experiment on response was conducted according to changing stepwise the influent concentration. Batch experiments on activity were carried out under several steady state conditions, using a kind of volatile fatty acid as a substrate. Transient responses of water quality are investigated in relation to the growth of bacterial groups which decompose volatile fatty acids. Based on the results, a dynamic model is proposed, in which attached biomass is categorized into 'active' biomass and inert organic matter. The transient response of substrate concentrations was clearly expressed by considering the growth of 'active' biomass. It was impossible to explain the responses when VSS was regarded as the biomass concentration in the model.

DOI： 10.2166/wst.1991.0585

Language：Japanese   Publishing type：Research paper (scientific journal)  

Evaluation of Methanogenic Activity Test Using Glass Vials

DOI： 10.2965/jswe1978.13.121

Language：Others   Publishing type：Research paper (scientific journal)  

A kinetic estimation method for the evaluation of active biomass concentration of acetate utilizing methanogen in mixed culture is proposed and discussed, based on the Monod model. Batch experiments were conducted using an enrichment culture of acetate utilizing methanogen in three different dilution levels to ascertain availability of the estimation method.“Active” biomass concentrations were kinetically estimated by both acetate consumption and methane production rates. Both estimated biomass concentrations were proportional to the dilution levels of the enrichment culture. The simultaneously estimated maximum specific growth rate was in good agreement with the literature values in the pure cultures. The changes of acetate and methane concentrations with time in the experiments were clearly explained by the Monod model with the estimated values. Then the estimation method was applied to the determination of concentration of acetate utilizing methanogen in a sewage digester sludge. It was shown that the “active”acetate utilizing methanogen occupied only 1-2% of VSS component. From these results, the “active” biomass concentration is shown to be very useful as a biomass index for the evaluation of treatment efficiency in mixed culture systems which contain non-biomass, such as sediments and sludges.

DOI： 10.11532/proes1983.26.9

Responsible for pages：Part 2 Environmental Change of Lake, "Chapter 4 Impact of Human Activities on the Water Environment of Lake Taifu Watershed"   Language：English   Book type：Scholarly book

Part 2 Environmental Change of Lake, "Chapter 4 Impact of Human Activities on the Water Environment of Lake Taifu Watershed"

Language：Japanese   Book type：Scholarly book

Language：Japanese   Book type：Scholarly book

Event date： 2023.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡大学   Country：Japan  

Event date： 2023.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡大学   Country：Japan  

Event date： 2022.11 - 2023.12

Language：Japanese  

Venue：いわて県民情報交流センター（アイーナ）（岩手県盛岡市）   Country：Japan  

This study is investigated to the competition between cyanobacterium Microcystis aeruginosa and diatom Nitzschia palea that can increase their cell number in a favorable environment for the occurrence of water bloom. We particularly focused on the temperature and pH effects on the inhibition effects of M. aeruginosa by N. palea. The maximum cell yield of M. aeruginosa reduced by approximately 50 % in the co-culture with N. palea at 15–30 ℃ as compared to that in the monoculture. N. palea also reduced the maximum cell yield of M. aeruginosa by 33, 54 and 66 % at pH 7.0, 8.0 and 9.0, respectively. N. palea reduced M. aeruginosa growth in the culture condition where water bloom is likely to occur. However, M. aeruginosa remained the dominant species in co-culture at 20–30 ℃ or pH 7.0–8.0. It is necessary to artificially increase the relative abundance of N. palea for enhancing the inhibition effect of M. aeruginosa.

Event date： 2022.11

Language：Japanese  

Venue：熊本大学   Country：Japan  

Event date： 2022.11

Language：Japanese  

Venue：熊本大学   Country：Japan  

Event date： 2022.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本大学   Country：Japan  

Event date： 2022.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本大学   Country：Japan  

Event date： 2022.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本大学   Country：Japan  

Event date： 2022.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本大学   Country：Japan  

Event date： 2022.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本大学   Country：Japan  

Event date： 2021.7 - 2019.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福島県郡山市   Country：Japan  

福島第一原発事故により環境中に多量の放射性物質が放出された。中でも137Csは長期的に環境へ影響を与え続けるため、環境中のCs⁺除去技術が必要とされている。本研究では活性炭の陽イオン吸着能に着目して、国内で豊富な森林資源を炭化させて木炭とし、環境中のCs⁺回収に活かせないかと考えた。試料としてスギとブナの未処理木炭とそれらに熱硝酸処理1) を施した賦活化木炭を用いてCs吸着能の評価を行った。また、木炭は焼却により大幅な減容化が可能であり、処分に要する費用や保管時の負担軽減が期待される。本研究ではCs⁺吸着後の木炭に対し電気マッフル炉を用いて焼却を行い、その際の木炭の減容化率と焼却灰中のCs⁺回収率を評価した。

Event date： 2021.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Zoom   Country：Japan  

Event date： 2021.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Zoom   Country：Japan  

Event date： 2021.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Zoom   Country：Japan  

Event date： 2021.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Zoom   Country：Japan  

Event date： 2021.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Zoom   Country：Japan  

Event date： 2020.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Kumamoto   Country：Japan  

Event date： 2020.10

Language：English   Presentation type：Oral presentation (general)  

Venue：Wenzhou University   Country：China  

Event date： 2020.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市西区   Country：Japan  

世界規模で水資源は貴重であり、水不足は深刻な問題である。国内でも一部地域で水問題が発生し、福岡市と糸島市においても一級河川が無く、渇水が起こりやすい。その水量的な問題の対策方法の一つとして再生水の利用が考えられている。2003年に福岡市では再生水に関する条例が制定され、大型建築物での再生水の使用が義務付けられた。さらに、九州大学では伊都地区へのキャンパス移転が2018年に完了し、学内人口もここ10数年で大きく増加した。また、伊都地区周辺地域では移転以前から農作物等への塩害が問題となっている。地下水を農業用水として広く利用しているため、地下水位の低下と渇水の影響により、地下水域への海水流入が憂慮された。このような福岡市の条例化や移転前後における諸問題を受け、2004年に学内に給水センターが建設された。給水センターは、大学内で生じた雑排水に浄化処理を施した再生水を供給している。また、節水効果と同時に、再生水は経費面においても安価である1), 2)。 本研究では、給水センター内の再生水処理施設の運転手法を模擬可能なモデルを構築し、それを基に、より一層の節水および経費削減のための運転手法の提案ならびにその節減効果の評価を行った。

Event date： 2020.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市西区   Country：Japan  

アオコは、悪臭の発生、酸欠による魚の斃死、浄水過程のろ過障害など、様々な問題を引き起こす。アオコの発生を抑制する対策として、浚渫や覆砂、凝集剤の散布などが挙げられる一方で、コスト面や環境への影響が大きい。そこで環境負荷の小さい省エネルギーな生物利用による対策に着目した。沈水植物であるセキショウモとアオコ(Microcystis spp.)との生物間相互作用を検討した際、セキショウモの有無によらずアオコが急減した。その原因を検討した結果、珪藻類のNitzschia sp. が直接Microcystis colony に侵入し、アオコの沈降、分解を促す現象が観察された。Nitzschia sp. は河川や湖沼、鉱泉など広く分布している在来種である。外来生物導入、遺伝子汚染の問題もクリアしているため、将来的に有望な応用生態工学的アオコ対策法として期待できる。本研究では、アオコの分解を促すNitzschia paleaの生理的特性を解明することを目的とした。N. paleaは、佐賀県の藤ノ平ダムから採取したNitzschia sp. を同定したものであり、それを使用する。N. paleaの生理的特性が判明すると工業的にN. paleaを生産して水域に散布し、アオコの増殖を抑制できる可能性がある。また、湖沼の栄養塩濃度からN. paleaの増殖速度を推定してN. paleaによるアオコの増殖抑制シミュレーションモデルが構築できる可能性もある。

Event date： 2020.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市西区   Country：Japan  

東北地方太平洋沖地震により発生した福島第一原発の事故で、大量の放射性物質が環境中に放出された。特に137Csの半減期は約30年と長く、長期的に環境へ負荷を与え続けるため、環境中のCs+を除去する技術が必要とされている。一方で、下水汚泥を含む汚泥は日本で排出される産業廃棄物の約42%を占めており、排出量の削減が必要である。下水汚泥のうち9%が溶融され、得られる汚泥溶融スラグは埋め立てや建築資材として利用されているが、埋め立て処分にも限界があり、新しい有効活用の方法が求められている。豊原らは、下水汚泥溶融スラグを熱アルカリ処理することで高いCs+吸着能を発揮するゼオライトを合成した。これにより、Cs⁺吸着能は約9倍となる一方で、Na＋やK＋などの高濃度の陽イオンが共存する場合にはCs⁺吸着が著しく阻害され、吸着能が低くなることを示した。これらを参考に、下水汚泥溶融スラグを用いて高いCs⁺吸着能を発揮するゼオライトの合成条件を明らかにするため、処理温度やスラグの産地などの条件を検討した。また吸着能評価としてCsCl aq及び陽イオン共存CsCl aqからのCs⁺吸着実験を行った。

Event date： 2019.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：岡山県岡山市   Country：Japan  

Basic research on the occurrence and growth mechanism of cyanobacteria as well as methods to prevent growth have been studied for many years. However, excessive cyanobacteria growth is still occurring frequently in lakes and reservoirs in various places. In recent years, ecological engineering methods have been considered due to their sustainability and energy saving nature. In this study, the hypothesis of whether diatom Nitzschia palea has the growth inhibitory effect on Microcystis aeruginosa (NIES-102) and the water blooms (Microcystis spp. collected from the pond) will be investigated. Moreover, since the wavelength of the optimal light for algae and cyanobacteria to grow varies depending on the species, investigation of the wavelength which suppresses the growth of M. aeruginosa will also be carried out. This will be done in combination with using the competitive nature of N. palea and by using LED irradiation. The results of the empirical investigation showed that in the high nitrogen concentration conditions, the growth of M. aeruginosa was inhibited by the addition of N. palea. However, despite the addition of N. palea and the silicate nutrient to the water blooms collected from the pond, it was not possible to confirm the growth inhibition of the cyanobacteria bloom. In the monoculture, irradiation of blue LED causes N. palea to grow, while M. aeruginosa had suppressed growth. Also, the growth of M. aeruginosa was suppressed by about 78% when compared to the used of monoculture and by adding N. palea under the condition of irradiating yellow LED at 25°C.

Event date： 2019.8

Language：English   Presentation type：Oral presentation (general)  

Venue：Marriott Hotel Putrajaya, Malaysia   Country：Malaysia  

This study reports the production ol synthetic zeolrte from sewage sludge molten slag (bio-slag) by alkali hydrothernral treatment. The bio-slag is treated with 1.0 N NaOH at 140C for 24 hr. The zeolite properties of modified bio-slag were identified by using surface area measurenrent, FESEM observation, XRF, XRD investigation and cation exchange capacity [CEC] analysis. The experimental results exhibit that the sutface area and the pore volume of the modified bio-slag increased almost 10 times. The FESEM obserwations showed that the modified bio-slag is highly porous. The XRF analysis indicates that the ratio of SiO2/Al23 in the slag is improved from 2.52 to 2.96 after the modification process which increases the strength of zeolite structure. The XRD analysis confirms that the zeolite X, zeolite Y, zeolite A, and sodalite were formed on the surface of the modified bio-slag. Importantly, the CEC of the modified bio-slag drastically improved almost 2 times due to the formation of synthetic zeolites. Therefore, the developed synthetic zeolite could be used as an emerging material for wastewater treatment, soil decontamination etc.

Other Link： https://itma.upm.edu.my/activities/isamn_2019_3rd_international_symposium_on_advanced_materials_and_nanotechnology-19103?L=en

Event date： 2019.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福島県郡山市   Country：Japan  

福島第一原子力発電所の事故により、大量の放射性物質が放出された。中でも137Csは半減期が約30年と長く、長期的な汚染が懸念されている。一方、現代ではプラズマ技術が様々な工学分野で幅広く応用されている。なかでも大気圧下でのプラズマは簡便な発生方法であること、試料の比表面積に影響をほとんど及ぼさないなどの利点がある。また、Kodamaらは活性炭に大気圧非平衡プラズマ処理を行うことで活性炭の陽イオン吸着能が向上することを明らかにした1)。そこで、本研究では137Csを除去する吸着剤として、竹炭および活性炭を利用するためにプラズマ処理を施し、処理後のCs⁺吸着能に与える影響を解明した。

Event date： 2019.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：長崎大学   Country：Japan  

東北地方太平洋沖地震により福島第一原発で事故が発生した。この事故により環境中に多量の放射性物質が放出された。特に、137Csの半減期は約30年と長く、長期的に環境へ負荷を与え続けるため、環境中のCs+を除去する技術が必要とされている。また現在日本では放置竹林が増加しており、環境面だけでなく防災面にも悪影響を及ぼすため、竹林の適切な管理を持続的に行いつつ、竹資源の循環的な利用の実現を目指す必要がある。
豊原らは、熱硝酸による酸化を行うことで竹炭の吸着能が約9倍となることを示し、Cs+吸着能の非常に高い吸着剤を開発した。しかし熱硝酸等の賦活化処理は取り扱いが難しく長時間を要する。一方で、小玉ら2)は活性炭に大気圧下での非平衡プラズマ処理を行うことでその表面に陽イオン吸着に有効とされる酸性官能基が導入されることを明らかにした。大気圧下でのプラズマ処理は減圧などの操作が必要なく簡便なこと、試料の比表面積にほとんど影響を与えないなどの利点を持つ。　　
以上のことより、本研究では大気圧非平衡プラズマを用いた竹炭のプラズマ賦活処理によるCs⁺吸着能の変化を評価した。また、酸性官能基量をプラズマ賦活前後で測定した。

Other Link： https://www.jsce.or.jp/branch/seibu/03_study/h_30kenkyu.html

Event date： 2019.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：長崎大学   Country：Japan  

近年、湖沼流域での水質汚濁による湖沼の富栄養化が深刻となり、それに伴ったアオコの異常増殖や被害などが報告されている。増殖したアオコの抑制は困難であり、初期発生の段階で抑制する必要がある。
アオコは一般的に底泥中に種場（Microcystis細胞の集積地)を形成し越冬し、発育条件が整った春～初夏に種場から水中に浮上し増殖する。浮上の条件として温度上昇が重要な要素であると報告されている。1)初期発生対策として種場の直接処理および種場から発生直後の浮遊細胞に対する処理が挙げられる。
アオコの初期発生を抑制する手法としては浚渫や凝集剤散布、水位低下による底泥の干し上げ等現場でも実施されているが、実際にはさまざまな問題を含んでおり、いまだにその手法は十分に確立されていない。また、アオコの主な優占種であるMicrocystis属に対して紫外線を照射することで増殖を抑制する効果があることが報告されている2)が、初期発生の種場のMicrocystis属に対しての研究例は少ない。本研究では、2018年にアオコが発生した、ため池、ダム貯水池のアオコおよび底泥を対象に紫外線発光ダイオード(UV-LED)照射によるMicrocystis属の増殖効果を明らかにすることを目的とした。

Other Link： https://www.jsce.or.jp/branch/seibu/03_study/h_30kenkyu.html

Event date： 2019.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：長崎大学   Country：Japan  

九州大学では2005年以降、大学の機能を段階的に伊都地区に移し、2018年に全移転を終えた。段階的な移転に伴い、学内人口も2007年の約5,200人から2018年には約18,700人と3倍以上増加した1)。そのため、学内人口増加による水需要の急速な拡大が懸念された。また、福岡市には一級河川が無いため、ダム等での十分な貯水が難しく渇水が起こりやすい。さらに、伊都地区周辺地域では移転以前から農作物等への塩害が問題となっている。地下水を農業用水として広く利用しているため、地下水位低下と渇水の影響により、地下水域への海水流入が憂慮された。大幅な水需要への対応と周辺地域の環境保全を図る目的で、環境安全センターが2004年に建設された。この施設では、生活排水や実験排水を浄化処理した水（再生水）を学内に供給している。
また、九大での再生水供給の運用費は、福岡市上水道料金より安価であると公表されている2)。従って、再生水を用いることで、どの程度運用面において経費削減になるかを調査した。加えて、運用面での経費削減の手法として如何なるものがあるか、今後の九大における再生水利用の在り方も踏まえて考察した。

Other Link： https://www.jsce.or.jp/branch/seibu/03_study/h_30kenkyu.html

Event date： 2018.7

Language：English   Presentation type：Oral presentation (general)  

Venue：National University of Singapore, Singapore   Country：Singapore  

In this study, the effective cesium adsorption from aqueous solution was experimented onto the sewage sludge molten (SSM) slag, modified by alkaline (NaOH) hydrothermal treatment. Batch adsorption experiments were carried out to investigate the effect of contact time, solution pH, adsorbent dose, different initial cesium ions concentrations, temperature and the effect of competitive ions on cesium adsorption. The adsorption isotherm, kinetic, and thermodynamic studies were also evaluated following the experimental results to explore the equilibrium conditions and the mechanism of cesium adsorption. A higher cesium removal efficiency of almost 100% (for 20-100 mg/L of initial cesium ions concentration) was achieved by the modified slag and the maximum adsorption capacity was found to be 52.36 mg/g compared with the raw slag. The higher adsorption performance of the modified slag may be due to the formation of artificial zeolites on its surface during the hydrothermal treatment process. In the competitive ions effect on cesium adsorption, the modified slag effectively captured the cesium ions in the presence of Na+ and K+, especially at their lower molar concentrations (1:10). Kinetic parameters were fitted by pseudo-second order model. The adsorption isotherms data of modified slag were well fitted to the Langmuir (R2=0.989) and Freundlich isotherms model　(R2=0.988). The thermodynamic studies indicated that the adsorption process by the modified slag was spontaneous and exothermic in nature. Moreover, the modified slag was reused several cycles (adsorption-elution-adsorption) without deterioration of its original adsorption performance. Therefore, it is expected that the SSM modified slag could be effectively used as cost-effective and a potential adsorbent for cesium adsorption from wastewater.

Other Link： http://www.iceae.org/ICEAE2018-program.pdf

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宮崎大学 木花キャンパス   Country：Japan  

アオコは腐敗による悪臭の発生、酸欠による魚の斃死、浄水過程のろ過障害など、近年様々な問題を引き起こしている。アオコを構成するMicrocystis aeruginosaをはじめとする植物性プランクトンは、光条件によって生育状態が異なることが知られている。本研究ではさらに、珪藻類がアオコと競合関係にあることにも着目し、競合条件下での照射光の波長の違いによるアオコの成長抑制の可能性を探ることを目的とした。

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宮崎大学 木花キャンパス   Country：Japan  

東北地方太平洋沖地震により福島第一原発で事故が起きた。この事故により環境中に多量の放射性物質が放出され、いまだ海や地下水への漏えいや土壌汚染が問題となっている。放射性物質の中でも特に、137Csの半減期は約30年と長く、長期的に環境へ影響を与え続けるため、環境中のCs⁺を除去する技術が必要とされている。
　また、現在日本ではスギやヒノキなどの放置人工林が問題になっている。手入れのされていない人工林は生態系の単一化や地盤強度の低下による土砂崩れなどを引き起こす。福島県は森林資源が豊富であり、スギ人工林の面積が非常に大きい。そこで、活性炭の陽イオン吸着能に着目し1)、豊富なスギ材を環境中のCs⁺回収に活かせないかと考え、また、樹種による吸着能力の比較を行うため、スギ、ブナによる木炭を用いて実験を行った。

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宮崎大学 木花キャンパス   Country：Japan  

近年、世界的なリン資源の枯渇が危惧され、その効率的な回収・再利用システムの確立が求められている。リン回収方法の一つとして多量のリンを含む下水を対象としたMAP（MAP：Magnesium Ammonium Phosphate）法がある。MAP法はマグネシウム薬剤を添加し、MAPの形態でリンを回収するプロセスゆえに、マグネシウム薬剤のコストの高さが課題である。道財らの報告によると、リン酸イオンのポリマーであるポリリン酸の形から MAP を形成すると、リン酸イオンから形成する場合と比べて、マグネシウム薬剤の削減ができた1) 。また、下水処理場における配管閉塞課題の改善につながる可能性がある。しかし、課題としてポリリン酸回収率の向上が求められる。従って、本研究では、ポリリン酸回収率の向上を図るため、MAP 粒子を種晶として使用し、適切な添加量とpH条件について検討した。

Event date： 2017.9

Language：Japanese  

Venue：九州大学伊都キャンパス   Country：Japan  

福島第一原発の事故により、多量の放射性物質が環境中に放出された。特にセシウム137は長い半減期を持ち、長期的に環境を汚染し続けることから早急な対策が求められている。また、日本各地で竹林化が進行している。竹は単一な種による生態系を形成し、また地盤の強度を弱めて土砂災害を引き起こしやすくする。したがって伐採による継続的な管理が必要であるが、現状では、竹材の利用価値は低く、有効活用することが難しい。　藤田ら1) は竹炭の炭化温度を変えることによってCs+の吸着能が変化することを明らかにした。また、竹内ら2)は活性炭に熱硝酸処理を施すことでCs+の吸着能が向上することを明らかにした。KhandakaerらはX線光電子分光法(XPS: X-ray photoelectron spectroscopy）を用いて熱硝酸処理前後の竹炭粒子表面の組成分析を行い、賦活処理によってグラファイトが71.1%から40.2%に減少し、カルボキシル基が2.70%から6.86%に、カルボニル基が0.52%から6.79%に増加することを明らかにした。Cs⁺の吸着は主に竹炭表面の酸性官能基におけるイオン交換現象が担っているといわれており、熱硝酸処理によって酸性官能基を導入し、Cs⁺吸着能を向上させることができる。そこで本実験では様々な条件を変えて竹炭の熱硝酸酸化を行い、各処理条件がCs⁺吸着能の向上に与える影響を解明した。

Event date： 2017.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Qingdao   Country：China  

The surface chemistry and the structural properties of activated carbon can be altered by the acidic modification. The objective of this study is to investigate the changes occurring in bamboo charcoal (BC) during activation with concentrated nitric acid. Low temperature (500˚C) carbonized BC has been prepared and oxidized with 70% concentrated boiling nitric acid (BC-AC). The porous properties of the BC are analyzed with nitrogen adsorption isotherm at 77 K. The surface structure is observed by Field emission scanning electronic microscope (FESEM) and the surface functional groups are examined by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and the pH of the point of zero charge (pHPZC). The results reveal that severe oxidation with HNO3 considerably decreases the surface area of BC with enhanced pore widening and FESEM observation demonstrates the erosive effect of oxidation. The FTIR analysis detects that some absorption bands are assigned for carboxyl, aldehyde and ketone groups on BC-AC. The XPS analysis also clearly shows that the ratio of oxygen and acidic functional groups has been enriched significantly on the BC-AC. The low pHPZC value of BC-AC confirms that the surface is highly acidic for the fixation of acidic functional groups on surface. In general, the existence of the abundant amount of acidic functional groups on adsorbents enhances the sorption of heavy metals ions in aqueous solution. Therefore, it is strongly expected that the modified BC, activated under the proposed conditions would be a promising ion exchanger in aqueous solution and can be applied for the adsorption of different heavy metal ions and radioactive materials from effluent.

Other Link： http://iopscience.iop.org/article/10.1088/1755-1315/82/1/012002/pdf

Event date： 2017.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本大学　黒髪キャンパス   Country：Japan  

本研究では、活性汚泥から抽出したポリリン酸を適用したMAP法において、活性汚泥の加熱処理条件、活性汚泥の加熱処理溶液中のMgとNH4+濃度に関する条件、MAP形成時の運転条件、というMAP形成過程における3項目の条件について段階的に設定する実験的研究を行った。本実験により、リン回収率の面で最適な条件を詳細に検討した

Event date： 2017.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本大学　黒髪キャンパス   Country：Japan  

LED 照射による水環境改善効果

Event date： 2017.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：佐賀大学 本庄キャンパス   Country：Japan  

アオコの異常増殖は長年に渡り世界的な問題となっている。アオコは主に植物性プランクトンで構成され、光条件によって生育状態が異なる。また、高等生物では照射される光の波長の違いが植物の成長に影響を与えることが知られている。本研究では、照射光の波長の違いによるアオコ成長の抑制の可能性を探った。アオコと、アオコを構成する代表的なシアノバクテリアであるMicrocystis aeruginosaの菌株へ波長の異なるLED光を照射し、それぞれの成長の違いを見ることで、その影響を検討した。

Event date： 2017.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：佐賀大学 本庄キャンパス   Country：Japan  

近年、世界中でリンの回収・再資源化が求められている。その回収技術の一つとして、マグネシウム薬剤を添加してリンをリン酸マグネシウムアンモニウム(MAP)として回収する方法がある。MAP法では化学反応に必要なマグネシウム薬剤が高価であることから、コストの面で改善の余地がある。道財らの研究で、リン酸イオンのポリマーであるポリリン酸の形からMAPを形成すると、リン酸イオンから形成するのと比べて、マグネシウム薬剤の削減が可能である ことが分かっている。しかし、その方法はリン回収率の低さが課題である。そこで、ポリリン酸回収率の向上を図るため種晶に注目した。本研究では、ポリリン酸を多量に含んだ活性汚泥の加熱処理水に、MAP法の適用における種晶添加の効果を検討した。また、種晶添加量による影響、pH調整の有無についての検討も行った。

Event date： 2016.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東北工業大学八木山キャンパス   Country：Japan  

WATER PURIFICATION BY LED IRRADIATION IN DECOMPOSING WITHERED MICROCYSTIS

Other Link： http://committees.jsce.or.jp/hydraulic/node/56

Event date： 2016.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州産業大学   Country：Japan  

Development of cesium ion adsorption material using sewage sludge molten slag
―The effect of component of the slag, surface treatment and coexisting ion ―

Event date： 2016.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州産業大学   Country：Japan  

Cultivation of useful plants over the water surface receiving treated sewage

Event date： 2016.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州産業大学   Country：Japan  

Phosphorus recovery by heating extracted polyphosphate from activated sludge

Event date： 2016.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：国立大学法人佐賀大学   Country：Japan  

Research of preventing water blooms through destructing Microcystis colonies by diatom

Event date： 2015.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：日本大学工学部   Country：Japan  

POLYPHOSPHATE RECOVERY FROM SEWAGE SLUDGE AS MAGNESIUM AMMONIUM PHOSPHATE AND ITS FORMING ABILITY

Event date： 2015.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都大学   Country：Japan  

本研究はアオコと競争関係にある植物プランクトン（珪藻，緑藻等），特にアオココロニー(Microcystis colony)に付着・侵入し寄生化する珪藻類に着目し，その，アオコ抑制対策としての適用性について室内外の培養実験に基づき検討したものである．今回は，検討結果のうち，化学的条件制御法について報告する．

Event date： 2015.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：金沢大学   Country：Japan  

近年，世界各地の湖沼では水質汚濁による富栄養化問題が深刻となり，それに伴うアオコの異常増殖によって利水障害などが頻繁に報告されている。また，紐状接触材は隔離水塊内において動物プランクトンの生息場となり，植物プランクトンの捕食を促し，クロロフィルa(Chl.a)を低減させる効果があると報告されている1)。そこで，本研究では，アオコが発生しているダム湖に浸漬した紐状生物付着担体によるアオコ抑制の水質浄化能を検討した。
２．実験方法
2014年7月～9月の期間アオコが発生している打上ダム湖(佐賀県)に約一か月半，紐状生物付着担体を浸漬したあとにダム湖に設置された隔離水塊内で馴致した。その後，採取した湖水を，アオコが同じ濃度になるように6個のビーカーにそれぞれ2Lずつ入れ対照区と処理区の各3連に分けた。長さ15cmの馴致した生物付着担体を処理区の3個のビーカーに投入し，温度25℃の恒温室に設置した。12h明(3400lux)12h暗の光条件下で14日間培養しChl.a濃度の測定及び植物プランクトン組成の同定を行った。

Event date： 2015.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：金沢大学   Country：Japan  

福島第一原子力発電所事故以降、環境中に放出された放射性物質による湖沼や地下水の汚染が深刻な問題となっており、特に半減期の長いCsの除去及び回収が必要とされている。また、下水処理場で発生する溶融スラグは安価に入手できる吸着材として排水処理に多く利用されている。本研究では、下水汚泥溶融スラグ(以下、溶融スラグ、SL)を使用した水中のセシウムイオン(以下、Cs+)吸着除去を目的とし、その吸着メカニズムを検討した。

Event date： 2015.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：琉球大学   Country：Japan  

現在、湖沼や貯水池などの閉鎖性水域では、アオコの大量発生による水質悪化が深刻な問題となっている。アオコの防除として物理的、化学的対策法が実施されているが、莫大なコストやエネルギーを要し、自然環境への影響も懸念されている。そのため、経済的で、維持管理が容易な二枚貝による生物学的防除法が注目されている。二枚貝はろ過摂食を行うことで水中の懸濁微粒子を取り除き、水質浄化機能を発揮しているが、二枚貝のアオコ除去能力に関する基礎的な研究はまだ少ない。そこで、本研究では、アオコ除去の水質浄化法を検討するために、入手が容易なドブガイ(Anodonta woodiana)、ヌマガイ(Sinanodonta lauta）と、淡水真珠の母貝としても利用されているヒレイケチョウガイ(Hyriopsis cumingii )の3種類の二枚貝を用い、アオコが発生しているダム湖を対象に室内実験による二枚貝のろ過速度、呼吸速度、排泄速度の種間差異を調べ、アオコ除去能の比較を行った。

Event date： 2015.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：琉球大学   Country：Japan  

我が国におけるリン鉱石の埋蔵量は皆無であるため、環境中に排出されているリンの回収・再資源化が求められている。その中で、特に多量のリンを含んでいる下水からのリン回収が注目されている。その回収技術の一つとして、マグネシウムを用いてリンをリン酸マグネシウムアンモニウム(MAP)として回収するMAP法がある。このMAP法のコスト・効率面の改善策として、比較的低温で加熱処理することにより、リン酸のポリマーであるポリリン酸の形でリンを活性汚泥から多量に抽出できるHeatphos法1)に注目した。本研究では、ポリリン酸を多量に含んだ加熱処理水にMAP法を適用し、MAP形成の確認と、リン回収率、必要なMg量、pH条件という3点の形成能の評価を行った。

Event date： 2015.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：琉球大学   Country：Japan  

2011年に発生した福島第一原子力発電所での事故により、環境に多量の放射性物質が放出された。この事故により汚染水の処理、放射性物質の海や地下への流出など環境に与える影響が懸念されている。特に137Csの半減期は長く、長期間に渡り放射能を放出するため環境中からCs+を回収するための新たな方法が必要とされている。また現在全国の里山では放置竹林の増加が問題となっている。放置竹林は土砂災害や生態系破壊の原因となるため、定期的な伐採などの適正な管理が必要となる。しかしながら現在ではその伐採した竹の資源としての利用価値は低く、何らかの形で有効に活用する方法が求められている。
　そこで竹を炭化させることで竹炭とし、その竹炭をCs+吸着材として利用することを目指した。藤田ら1）は、低温(400℃)で炭化した竹炭がCs+吸着に有効であり、その主な吸着メカニズムは、竹炭表面に存在する酸性官能基によるものであることを明らかにした。また、内川ら2）は竹炭をNaOHで前処理し、酸性官能基にNaを担持させることにより吸着能が向上することを明らかにした。以上の研究を踏まえ、本研究では、濃度及び種類の異なる塩基による竹炭の前処理、及びCs+溶液中に共存させた1価の陽イオン、この2点が竹炭によるCs+吸着能に及ぼす影響を検討した。

Event date： 2014.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州大学医学部百年講堂中ホール１   Country：Japan  

近年、湖沼等の閉鎖性水域では富栄養化によるアオコ（主に藍藻類のMicrocystis属）の大量発生が深刻な問題となっている。これに対処するために、さまざまなアオコ防除法が実施されているが、流域社会構造の問題等から対応が進捗せず、アオコ防除施設の設置や運用には多くの費用を要する等の問題を抱えている。今日の社会情勢より省エネルギーで持続性があり、水域環境の改善にも効果のある対策が求められている。そこで、本研究では、Microcystis属と競合関係にある珪藻1)を活性化させてMicrocystis属の増殖を抑制することを目的として、ケイ酸供給による室内実験及び現場実験を行い、Microcystis属の生態工学的防除方法の有効性を検討した。

Event date： 2014.10

Language：English   Presentation type：Oral presentation (general)  

Venue：Jingyi Hotel, Beijing, China   Country：Japan  

Comprehensive Evaluation of Poly-Phosphate Release from Sewage Sludge with Thermal Treatment

Event date： 2014.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都大学 吉田キャンパス   Country：Japan  

Microcystis Colony 破壊 Diatomを用いたアオコ防除対策法の研究開発

Event date： 2014.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：大阪大学   Country：Japan  

近年、湖沼等の閉鎖性水域では富栄養化によるアオコ（主に藍藻類のMicrocystis属）の大量発生が深刻な問題となっている。これに対処するために、さまざまなアオコ防除法が実施されているが、流域社会構造の問題等から対応が進捗せず、アオコ防除施設の設置や運用には多くの費用を要する等の問題を抱えている。今日の社会情勢より省エネルギーで持続性があり、水域環境の改善にも効果のある対策が求められている。そこで、本研究では、Microcystis属と競合関係にある珪藻1)を活性化させてMicrocystis属の増殖を抑制することを目的として、ケイ酸供給による室内実験及び現場実験を行い、Microcystis属の生態工学的防除方法の有効性を検討した。

Event date： 2014.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：大阪大学   Country：Japan  

2011年3月11日に発生した福島第一原子力発電所での事故は甚大な被害をもたらし、放射性物質の放出は今尚続いている。特に、137Csの半減期は非常に長く、環境中から効率的に回収していくことが重要である。また、全国の里山では放置竹林の増加が問題となっている。しかしながら現代では竹材の資源としての利用価値は低く、何らかの形で有効に活用する方法が求められている。
そこで本研究は、Cs＋の吸着材としての竹炭の利用を目指した。また、その吸着能の向上のために、溶液の初期pHの調整を行うこと、竹炭に対して酸・塩基による洗浄処理を行うこと、以上の2点が吸着能に及ぼす影響を検討した。

Event date： 2014.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡大学   Country：Japan  

Event date： 2014.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡大学   Country：Japan  

Event date： 2014.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡大学   Country：Japan  

Event date： 2013.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Paris   Country：France  

Effects of Macrophyte Vallisneria asiatica Biomasses on the Algae Community

Event date： 2013.11

Language：English   Presentation type：Oral presentation (general)  

Venue：北海道大学   Country：Japan  

The Evaluation of Sinanodonta woodiana Application Feasibility as a Microcystis-Blooming Removal Tool in Microcosm Experiments

Event date： 2013.11

Language：English   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Application Feasibility of Anodonta woodiana as a Biomanipulation Tool in Lake Taihu

Event date： 2013.11

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Venue：福岡市   Country：Japan  

Event date： 2013.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Water Pollution of Lake Taihu and Solutions for Environmental Problems

Event date： 2013.11

Language：English   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Event date： 2013.11

Language：English   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Restoration Conditions of Submerged Macrophyte Vallisneria asiatica in Eutrophic Lake Taihu, China

Event date： 2013.9

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Venue：福岡市   Country：Japan  

Event date： 2013.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：大阪府立大学   Country：Japan  

Event date： 2013.9 - 2013.8

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：日本大学津田沼キャンパス   Country：Japan  

Event date： 2013.9 - 2013.8

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：日本大学津田沼キャンパス   Country：Japan  

Event date： 2013.8

Language：English   Presentation type：Oral presentation (general)  

Country：Singapore  

A Comparison of the Mussel Anodonta woodiana’s Acute Physiological Responses to Different Algae Diets

Event date： 2013.7

Language：English   Presentation type：Oral presentation (general)  

Venue：Guangzhou   Country：China  

The Crystallization of Struvite by Recycling Poly-Phosphate Released from Sewage Sludge after Thermal Treatment

Event date： 2013.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：岩手県一関文化センター   Country：Japan  

Event date： 2013.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本大学   Country：Japan  

Event date： 2013.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：大阪工業大学   Country：Japan  

Event date： 2013.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本大学   Country：Japan  

2011年3月11日に発生した東日本大震災では、福島県双葉郡大熊町にある福島第一原子力発電所が被災し、大量の放射性物質(137Cs、131Iなど)が環境中に放出され、種々の環境汚染が福島県を中心に引き起こされた。特に、137Csの半減期は約30年と非常に長く、長期間にわたって環境に影響を与え続けるため、効率的に回収していくことが重要となっている。
　また、現在全国の里山において放置竹林が増加し、その急激な成長による竹林面積の拡大が社会問題となっている。そのため定期的な伐採等による竹林の適正な管理が必要である。しかし、竹材の需要は減少する一方であり、伐採後の竹の有効活用が求められている。
　本研究では、竹を持続可能な循環資源ととらえ、Cs+吸着材としての竹炭の利用を目指した。そこで、竹炭の炭化温度、ならびに、溶液中に共存する陽イオンがCs＋吸着能に与える影響を検討した。

Event date： 2013.1

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Venue：福岡   Country：Japan  

Event date： 2012.12

Language：Japanese   Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Venue：上海交通大学   Country：China  

Event date： 2012.12

Language：Others   Presentation type：Oral presentation (general)  

Venue：上海交通大学   Country：China  

Impact of Human Activities on the water Environment of Lake Taihu Watershed and Solution for Environmental Problems
(Our Lakes: From the Present towards a Future Perspective)

Event date： 2012.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Tongji University, Shanghai, China   Country：China  

Event date： 2012.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Tongji University, Shanghai, China   Country：China  

Event date： 2012.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Tongji University, Shanghai, China   Country：China  

Event date： 2012.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Tongji University, Shanghai, China   Country：China  

Event date： 2012.11

Language：English   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Yang Cheng Lake, which is famous with the crab culture, now faces the deterioration of water quality. Ecological dam is designed for in situ remediation of contaminated water of crab culture. The device of ecological dam consists of ecological floating bed with the dimension of 2m long and 1m wide, and immobilized biological media with about 1.8m long which is fixed on the floating bed with one side and immersed in the lake water with another side. In this study, two in situ demonstration areas with dimension of 20m long and 10m wide are constructed in the crab culture farms to investigate the change of water quality. Each area is surrounded by seine to avoid crabs climbing into. In one demonstration area, 36 devices of ecological dam are connected and laid in surrounding, which are planted with water spinaches. The other demonstration area is established in contrast, in which there is no device of eco-dam. It is concluded that during three months’ operation, ecological dam shows a significant effect on the turbidity improvement. However nutrient removal in eco-dam area is not improved, especially for TN. On the contrary, TN shows an obvious increment because of the release of organic nitrogen from the sediment under the condition of weak water exchange. It needs a long time to observe the remediation effect of ecological dam on the contaminated crab culture water.

Event date： 2012.11

Language：English   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Serious eutrophication is appearing in the Lake Taihu which is the third largest freshwater lake in China. Therefore, the water quality in Lake Taihu should be improved immediately. To improve water quality of the lake and control algae bloom, the effect of Vallisneria asiatica which is one of the macrophytes spread over Lake Taihu, with different biomass on water quality and algae was researched. The results showed that in the laboratory experiments, DTN, DTP, and turbidity decreased and the biomass of Microcystis sp. reduced with the increase of biomass of Vallisneria asiatica. Therefore, it was expected that Vallisneria asiatica could control an excess of Microcystis sp. in Lake Taihu. Furthermore, we discovered that during experimental period, lots of diatom (Nitzschia sp.) appeared in the Microcystis sp. community resulting in settling down of algae in case of small quantity of Vallisneria asiatica by microscopy. This may be one of the important reasons which resulted in the sharp decrease of the biomass of Microcystis sp. At the same time, epiphytic Cocconeis sp. appeared while Nitzschia sp. lessened in the tanks with large quantity of Vallisneria asiatica, which indicated that there was competition between epiphytic Cocconeis sp. and Nitzschia sp.

Event date： 2012.11

Language：English   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

The bivalve Sinanodonta woodiana is widely distributed throughout Chinese freshwaters and is an important economic pearl mollusk. Recently, S. woodiana as a tool in biomanipulation of lakes in China due to its strong suppression of phytoplankton, have been attracted increasingly more attention. In order to evaluate the impact of Microcystis-blooming pond water on the physiological behavior in a bioenergetic method, microcosm experiments were performed with natural eutrophic pond water and bivalves in laboratory for six days. In this experiment, filtration rate, absorption efficiency, oxygen consumption rate and ammonia excretion rate of S. woodiana were measured on the 0-day and 6-day, also the percentage changes of phytoplankton with different size scale were measured every two days for both control and treatment microcosms. The results indicated that after 6 days exposure to Microcystis-blooming pond water, the SFG (scope for growth) value as a measure of metabolic energy balance for S. woodiana increased and microplankton (>20 µm, including colony-forming Microcystis spp.) percentage was reduced obviously on the 6-day. This phenomenon indicates the percentage of phytoplankton with different size scale was obviously changed by the bivalves and meanwhile the bivalves themselves could grow well after six days’ exposure to this eutrophic water. Therefore, it can be concluded that S. woodiana can be used as an effective biomanipulation tool in eutrophic water.

Event date： 2012.10

Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Venue：福岡   Country：Japan  

Event date： 2012.10

Language：English   Presentation type：Oral presentation (general)  

Venue：Jirin, China   Country：China  

Fast consumption of high quality phosphorus mines and uneven distribution in the world
result in the shortage crisis for phosphorus, meanwhile lots of phosphate compounds which are
discharged into nature water bodies by human beings have already induced many environmental
problems. Because of this situation, phosphorus recovery from sewage sludge working in the aeration
tank of wastewater treatment plant (WWTP) has been researched in the present study.
Poly-phosphate (poly-P) and total phosphate (T-P) accumulated inside activated sludge could be
released by thermal treatment at low temperature, 30% poly-P and 29% T-P could be released from
sludge by heating at 70˚C. Different kinds of pretreatments had been tested to improve phosphorus
release from activated sludge in thermal treatment; addition of chelating reagent at final concentration
of 2 mM before thermal treatment could improve the phosphorus release obviously, 68% poly-P and
53% T-P could be released into liquid phase. Approximately 85% T-P could be precipitated with
calcium at pH 11; it was interesting to find precipitation occurred in neutral condition without pH
adjustment.

Event date： 2012.8

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2012.3

Presentation type：Oral presentation (general)  

Venue：鹿児島大学   Country：Japan  

Event date： 2011.11

Venue：Fukuoka   Country：Japan  

Proposal of an Eco-Emgineering Environmental Improvement Strategy in the Lake Taihu, China： A Concept based on the Water Quality and the Biota

Event date： 2011.11

Presentation type：Oral presentation (general)  

Venue：Fukuoka   Country：Japan  

THE EFFECT OF CHELATING REAGENTS ON THE RELEASE OF PHOSPHORUS FROM SEWAGE SLUDGE DURING HEATING PROCESS

Event date： 2011.11

Presentation type：Oral presentation (general)  

Venue：Fukuoka   Country：Japan  

Phosphorus Removal Ability Intensified by Calcium Silicate Hydrates (CSH) in Ecological Technologies

Event date： 2011.11

Presentation type：Oral presentation (general)  

Venue：Fukuoka   Country：Japan  

PRELIMINARY STUDY ON ECOLOGICAL ENGINEERING METHODS OF WATER QUALITY IMPROVEMENT IN THE LAKE TAIHU

Event date： 2011.9

Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Venue：福岡   Country：Japan  

Event date： 2011.9

Presentation type：Oral presentation (general)  

Venue：福岡市役所   Country：Japan  

Event date： 2011.9

Venue：北海道大学   Country：Japan  

Japanese Society for Agricultural, Biological, and Environmental Engineers and Scientists
Annual Meeting 2011 Sapporo (JSABEES)
Hokkaido University, September 6-8, 2011

Event date： 2011.8 - 2011.9

Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Venue：University of Moratuwa   Country：Sri Lanka  

Event date： 2011.8

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2011.8

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2011.8

Presentation type：Oral presentation (general)  

Venue：Zhenozhou, Henan   Country：China  

Multiple Criteria Assessment of Ecosystem Services Sustained by Qinhuai River in Nanjing

Event date： 2011.3

Presentation type：Oral presentation (general)  

Venue：九州工業大学   Country：Japan  

Event date： 2011.3

Presentation type：Oral presentation (general)  

Venue：九州工業大学   Country：Japan  

Event date： 2011.3

Presentation type：Oral presentation (general)  

Venue：九州工業大学   Country：Japan  

Event date： 2010.11

Presentation type：Symposium, workshop panel (public)  

Venue：Fukuoka   Country：Japan  

Event date： 2010.11

Presentation type：Symposium, workshop panel (public)  

Venue：Fukuoka   Country：Japan